Pre-configured prs transmission method for sidelink positioning, and apparatus therefor

ABSTRACT

The present invention relates to a pre-configured positioning reference signal (PRS) transmission method for sidelink positioning, and an apparatus therefor. A method for performing, by means of a positioning terminal, on-demand positioning in a new radio-vehicle to everything (NR-V2X) communication system, according to one aspect, comprises the steps of: transmitting a request PRS through a sidelink channel; receiving a response PRS corresponding to the request PRS from a neighboring terminal through the sidelink channel; receiving a measurement result corresponding to the request PRS from the neighboring terminal; and performing positioning on the basis of the response PRS and the measurement result, wherein the positioning terminal transmits, to the neighboring terminal, resource allocation information for transmission of the response PRS corresponding to the request PRS, and the measurement result may be received through a resource for V2X data transmission.

TECHNICAL FIELD

The present disclosure relates to sidelink positioning, and more particularly to a technology of transmitting a positioning reference signal (PRS) for sidelink positioning in a new radio-vehicle to everything (NR-V2X) system.

BACKGROUND ART

Wireless access systems have been widely deployed to provide various types of communication services such as voice or data. In general, a wireless access system is a multiple access system that supports communication of multiple users by sharing available system resources (a bandwidth, transmission power, etc.) among them. For example, multiple access systems include a Code Division Multiple Access (CDMA) system, a Frequency Division Multiple Access (FDMA) system, a Time Division Multiple Access (TDMA) system, an Orthogonal Frequency Division Multiple Access (OFDMA) system, a Single Carrier Frequency Division Multiple Access (SC-FDMA) system and multi carrier frequency division multiple access (MC-FDMA) system, etc.

Sidelink (SL) refers to a communication scheme in which a direct link is established between user equipments (UEs) and the UEs directly exchange voice or data without intervention of a base station (BS). SL is considered as a solution of relieving the BS of the constraint of rapidly growing data traffic.

Vehicle-to-everything (V2X) is a communication technology in which a vehicle exchanges information with another vehicle, a pedestrian, and infrastructure by wired/wireless communication. V2X may be categorized into four types: vehicle-to-vehicle (V2V), vehicle-to-infrastructure (V2I), vehicle-to-network (V2N), and vehicle-to-pedestrian (V2P). V2X communication may be provided via a PC5 interface and/or a Uu interface.

As more and more communication devices demand larger communication capacities, there is a need for enhanced mobile broadband communication relative to existing RATs. Accordingly, a communication system is under discussion, for which services or UEs sensitive to reliability and latency are considered. The next-generation RAT in which eMBB, MTC, and URLLC are considered is referred to as new RAT or NR. In NR, V2X communication may also be supported.

FIG. 1 is a diagram illustrating V2X communication based on pre-NR RAT and V2X communication based on NR in comparison.

For V2X communication, a technique of providing safety service based on V2X messages such as basic safety message (BSM), cooperative awareness message (CAM), and decentralized environmental notification message (DENM) was mainly discussed in the pre-NR RAT. The V2X message may include location information, dynamic information, and attribute information. For example, a UE may transmit a CAM of a periodic message type and/or a DENM of an event-triggered type to another UE.

For example, the CAM may include basic vehicle information including dynamic state information such as a direction and a speed, vehicle static data such as dimensions, an external lighting state, path details, and so on. For example, the UE may broadcast the CAM which may have a latency less than 100 ms. For example, when an unexpected incident occurs, such as breakage or an accident of a vehicle, the UE may generate the DENM and transmit the DENM to another UE. For example, all vehicles within the transmission range of the UE may receive the CAM and/or the DENM. In this case, the DENM may have priority over the CAM.

In relation to V2X communication, various V2X scenarios are presented in NR. For example, the V2X scenarios include vehicle platooning, advanced driving, extended sensors, and remote driving.

For example, vehicles may be dynamically grouped and travel together based on vehicle platooning. For example, to perform platoon operations based on vehicle platooning, the vehicles of the group may receive periodic data from a leading vehicle. For example, the vehicles of the group may widen or narrow their gaps based on the periodic data.

For example, a vehicle may be semi-automated or full-automated based on advanced driving. For example, each vehicle may adjust a trajectory or maneuvering based on data obtained from a nearby vehicle and/or a nearby logical entity. For example, each vehicle may also share a dividing intention with nearby vehicles.

Based on extended sensors, for example, raw or processed data obtained through local sensor or live video data may be exchanged between vehicles, logical entities, terminals of pedestrians and/or V2X application servers. Accordingly, a vehicle may perceive an advanced environment relative to an environment perceivable by its sensor.

Based on remote driving, for example, a remote driver or a V2X application may operate or control a remote vehicle on behalf of a person incapable of driving or in a dangerous environment. For example, when a path may be predicted as in public transportation, cloud computing-based driving may be used in operating or controlling the remote vehicle. For example, access to a cloud-based back-end service platform may also be used for remote driving.

In an NR-V2X system, UEs or a UE and an anchor node (AN) need to effectively provide control information related to positioning when sidelink positioning is performed.

Sidelink positioning may be used for positioning between vehicles, and for vehicle safety, highly reliable position information between vehicles needs to be provided, and positioning control information needs to be effectively used in consideration of various factors that affect positioning.

DISCLOSURE Technical Problem

An object of the present disclosure is to provide a method of transmitting a pre-configured PRS for sidelink positioning and an apparatus therefor.

Another object of the present disclosure is to provide a method of pre-configuring a PRS transmission resource in a physical sidelink feedback channel (PSFCH) and transmitting a PRS in an NR-V2X positioning system and an apparatus therefor.

Another object of the present disclosure is to provide a method of transmitted a pre-configured PRS for sidelink positioning and an apparatus therefor for minimizing transmission delay for positioning data to improve positioning performance by dynamically determining a V2X data resource for transmission of the positioning result according to pre-configured PRS resource allocation information and a positioning priority in the NR-V2X positioning system.

Another object of the present disclosure is to provide various sidelink positioning services by adaptively allocating a response PRS transmission resource to a neighbor UE according to various positioning modes.

It will be appreciated by persons skilled in the art that the objects that could be achieved with the present disclosure are not limited to what has been particularly described hereinabove and the above and other objects that the present disclosure could achieve will be more clearly understood from the following detailed description.

Technical Solution

According to an aspect, a method of performing on-demand positioning by a positioning user equipment (UE) in a new radio-vehicle to everything (NR-V2X) communication system includes transmitting a request positioning reference signal (PRS) through a sidelink channel, receiving a response PRS related to the request PRS from a neighbor UE through the sidelink channel, receiving a measurement result related to the request PRS from the neighbor UE, and performing positioning based on the response PRS and the measurement result, wherein the positioning UE transmits resource allocation information for transmission of the response PRS related to the request PRS to the neighbor UE and receives the measurement result through a resource for V2X data transmission.

According to an embodiment, the sidelink channel may include a physical sidelink feedback channel (PSFCH) for transmission of HARQ feedback information for sidelink data, and a resource for the request PRS and a resource for the response PRS may be allocated to one PSFCH resource or the resource for the request PRS and the resource for the response PRS are allocated to different PSFCH resources.

According to an embodiment, when the resource for the request PRS and the resource for the response PRS are allocated to the different PSFCH resources, a plurality of PSFCH-PRS groups including contiguous or non-contiguous slots may each be allocated for transmission of the request PRS and transmission of the response PRS.

According to an embodiment, the resource allocation information for transmission of the response PRS may be transmitted to the neighbor UE through at least one of 1^(st)-stage sidelink control information (SCI) of a physical sidelink control channel (PSCCH) or 2^(nd)-stage SCI of a PSSCH.

According to an embodiment, the resource allocation information for transmission of the response PRS may include information on a time gap between a transmission time of the request PRS in the positioning UE and a transmission time of the response PRS in the neighbor UE.

According to an embodiment, a request PRS ID related to the request PRS and a response PRS ID related to the response PRS may be the same.

According to an embodiment, a relationship between a response PRS ID related to the response PRS and a request PRS ID related to the request PRS may be pre-mapped or paired, a number of the response PRS IDs mapped or paired with the request PRS ID may be determined based on an on-demand positioning mode, and the on-demand positioning mode includes a 1:1 unicast positioning mode and a 1:N groupcast positioning mode.

According to an embodiment, the resource allocation information for transmission of the response PRS may include information on a plurality of candidate slots to be selected by the neighbor UE for transmission of the response PRS, and the plurality of candidate slots are periodically allocated.

According to an embodiment, the measurement result may be received through a slot overlapping the candidate slot selected by the neighbor UE for transmission of the response PRS or a closest slot among a plurality of slots reserved for the V2X data transmission.

According to an embodiment, the measurement result may be received through the V2X data transmission slot reserved or preoccupied based on a positioning priority related to the request PRS.

According to another aspect, a user equipment (UE) for performing on-demand positioning in a new radio-vehicle to everything (NR-V2X) communication system includes a radio frequency (RF) transceiver, and a processor connected to the RF transceiver, wherein the processor transmits a request positioning reference signal (PRS) through a sidelink channel, receives a response PRS related to the request PRS from a neighbor UE through the sidelink channel, receives a measurement result related to the request PRS from the neighbor UE, and performs positioning based on the response PRS and the measurement result, and the UE transmits resource allocation information for transmission of the response PRS related to the request PRS to the neighbor UE and receives the measurement result through a resource for V2X data transmission.

According to an embodiment, the sidelink channel may include a physical sidelink feedback channel (PSFCH) for transmission of HARQ feedback information for sidelink data, and a resource for the request PRS and a resource for the response PRS may be allocated to one PSFCH resource or the resource for the request PRS and the resource for the response PRS may be allocated to different PSFCH resources.

According to an embodiment, when the resource for the request PRS and the resource for the response PRS are allocated to the different PSFCH resources, a plurality of PSFCH-PRS groups including contiguous or non-contiguous slots may each be allocated for transmission of the request PRS and transmission of the response PRS.

According to an embodiment, the resource allocation information for transmission of the response PRS may be transmitted to the neighbor UE through at least one of 1st-stage sidelink control information (SCI) of a physical sidelink control channel (PSCCH) or 2^(nd)-stage SCI of a PSSCH.

According to an embodiment, the resource allocation information for transmission of the response PRS may include information on a time gap between a transmission time of the request PRS in the positioning UE and a transmission time of the response PRS in the neighbor UE.

According to an embodiment, a request PRS ID related to the request PRS and a response PRS ID related to the response PRS may be the same.

According to an embodiment, a relationship between a response PRS ID related to the response PRS and a request PRS ID related to the request PRS may be pre-mapped or paired, a number of the response PRS IDs mapped or paired with the request PRS ID is determined based on an on-demand positioning mode, and the on-demand positioning mode includes a 1:1 unicast positioning mode and a 1:N groupcast positioning mode.

According to an embodiment, the resource allocation information for transmission of the response PRS may include information on a plurality of candidate slots to be selected by the neighbor UE for transmission of the response PRS, and the plurality of candidate slots may be periodically allocated.

According to an embodiment, the measurement result may be received through a slot overlapping the candidate slot selected by the neighbor UE for transmission of the response PRS or a closest slot among a plurality of slots reserved for the V2X data transmission.

According to an embodiment, the measurement result may be received through the V2X data transmission slot reserved or preoccupied based on a positioning priority related to the request PRS.

Advantageous Effects

Various embodiments may advantageously provide a method of transmitting a pre-configured PRS for sidelink positioning in an NR-V2X positioning system and an apparatus therefor.

Various embodiments may advantageously provide a sidelink on-demand positioning and an apparatus therefor for effectively using a wireless resource by pre-configuring a PRS transmission resource in a physical sidelink feedback channel (PSFCH) and then transmitting a PRS in an NR-V2X positioning system.

Various embodiments may advantageously provide a method of transmitting a pre-configured PRS for sidelink positioning and an apparatus therefor for minimizing transmission delay for positioning data to improve positioning performance by dynamically determining a V2X data resource for transmission of the positioning result according to pre-configured PRS resource allocation information and a positioning priority in the NR-V2X positioning system.

Various embodiments may advantageously provide various sidelink positioning services by adaptively allocating a response PRS transmission resource to a neighbor UE according to various positioning modes.

It will be appreciated by persons skilled in the art that the effects that could be achieved with the present disclosure are not limited to what has been particularly described hereinabove and other advantages of the present disclosure will be more clearly understood from the following detailed description.

DESCRIPTION OF DRAWINGS

The accompanying drawings are provided to provide an understanding of the present disclosure, and are intended to illustrate various embodiments of the present disclosure and, together with the description of the specification, explain the principles of the present disclosure.

FIG. 1 is a diagram illustrating vehicle-to-everything (V2X) communication based on pre-new radio access technology (NR) RAT and V2X communication based on NR in comparison.

FIG. 2 is a diagram illustrating the structure of a long term evolution (LTE) system.

FIG. 3 is a diagram illustrating the structure of an NR system.

FIG. 4 is a diagram illustrating the structure of an NR radio frame.

FIG. 5 is a diagram illustrating a slot structure in an NR frame.

FIG. 6 is a diagram illustrating radio protocol architectures for sidelink (SL) communication.

FIG. 7 is a diagram illustrating user equipments (UEs) which conduct V2X or SL communication between them

FIG. 8 is diagram illustrating resource units for V2X or SL communication

FIG. 9 is a diagram illustrating signal flows for V2X or SL communication procedures of a UE according to transmission modes

FIG. 10 illustrates an exemplary architecture of a 5G system capable of positioning a UE connected to an NG-RAN or an E-UTRAN according to an embodiment of the present disclosure.

FIG. 11 illustrates exemplary implementation of a network for positioning a UE according to an embodiment of the present disclosure.

FIG. 12 is a diagram for explaining a pre-configuration PRS transmission method for sidelink on-demand positioning according to an embodiment.

FIG. 13 is a flowchart for explaining a sidelink on-demand positioning procedure in a positioning UE according to an embodiment.

FIG. 14 is a diagram for explaining a method of transmitting a response PRS by a neighbor UE when a V2X data slot is pre-reserved at a time when a response PRS needs to be transmitted according to an embodiment.

FIG. 15 is a diagram for explaining a method of transmitting a response PRS by a neighbor UE when a V2X data slot is pre-reserved at a time when a response PRS needs to be transmitted according to another embodiment.

FIG. 16 is a diagram for explaining a method of transmitting a response PRS by a neighbor UE when a V2X data slot is reserved at a time when a response PRS needs to be transmitted according to another embodiment of the present disclosure.

FIG. 17 is a flowchart for explaining a sidelink broadcast positioning procedure in an AN according to an embodiment.

FIG. 18 illustrates a communication system applied to the present disclosure.

FIG. 19 illustrates wireless devices applicable to the present disclosure.

FIG. 20 illustrates another example of a wireless device applicable to the present disclosure.

FIG. 21 illustrates a vehicle or an autonomous driving vehicle applied to the present disclosure.

BEST MODE

According to an aspect, a method of performing on-demand positioning by a positioning user equipment (UE) in a new radio-vehicle to everything (NR-V2X) communication system includes transmitting a request positioning reference signal (PRS) through a sidelink channel, receiving a response PRS related to the request PRS from a neighbor UE through the sidelink channel, receiving a measurement result related to the request PRS from the neighbor UE, and performing positioning based on the response PRS and the measurement result, wherein the positioning UE transmits resource allocation information for transmission of the response PRS related to the request PRS to the neighbor UE and receives the measurement result through a resource for V2X data transmission.

[Mode]

A wireless communication system is a multiple access system that supports communication of multiple users by sharing available system resources (a bandwidth, transmission power, etc.). Examples of multiple access systems include a CDMA system, an FDMA system, a TDMA system, an OFDMA system, an SC-FDMA system, and an MC-FDMA system.

Sidelink (SL) refers to a communication scheme in which a direct link is established between user equipments (UEs) and the UEs directly exchange voice or data without intervention of a base station (BS). SL is considered as a solution of relieving the BS of the constraint of rapidly growing data traffic.

Vehicle-to-everything (V2X) is a communication technology in which a vehicle exchanges information with another vehicle, a pedestrian, and infrastructure by wired/wireless communication. V2X may be categorized into four types: vehicle-to-vehicle (V2V), vehicle-to-infrastructure (V2I), vehicle-to-network (V2N), and vehicle-to-pedestrian (V2P). V2X communication may be provided via a PC5 interface and/or a Uu interface.

As more and more communication devices demand larger communication capacities, there is a need for enhanced mobile broadband communication relative to existing RATs. Accordingly, a communication system is under discussion, for which services or UEs sensitive to reliability and latency are considered. The next-generation RAT in which eMBB, MTC, and URLLC are considered is referred to as new RAT or NR. In NR, V2X communication may also be supported.

Techniques described herein may be used in various wireless access systems such as code division multiple access (CDMA), frequency division multiple access (FDMA), time division multiple access (TDMA), orthogonal frequency division multiple access (OFDMA), single carrier-frequency division multiple access (SC-FDMA), and so on. CDMA may be implemented as a radio technology such as universal terrestrial radio access (UTRA) or CDMA2000. TDMA may be implemented as a radio technology such as global system for mobile communications (GSM)/general packet radio service (GPRS)/Enhanced Data Rates for GSM Evolution (EDGE). OFDMA may be implemented as a radio technology such as IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, evolved-UTRA (E-UTRA), or the like. IEEE 802.16m is an evolution of IEEE 802.16e, offering backward compatibility with an IRRR 802.16e-based system. UTRA is a part of universal mobile telecommunications system (UMTS). 3rd generation partnership project (3GPP) long term evolution (LTE) is a part of evolved UMTS (E-UMTS) using evolved UTRA (E-UTRA). 3GPP LTE employs OFDMA for downlink (DL) and SC-FDMA for uplink (UL). LTE-advanced (LTE-A) is an evolution of 3GPP LTE.

A successor to LTE-A, 5th generation (5G) new radio access technology (NR) is a new clean-state mobile communication system characterized by high performance, low latency, and high availability. 5G NR may use all available spectral resources including a low frequency band below 1 GHz, an intermediate frequency band between 1 GHz and 10 GHz, and a high frequency (millimeter) band of 24 GHz or above.

While the following description is given mainly in the context of LTE-A or 5G NR for the clarity of description, the technical idea of an embodiment of the present disclosure is not limited thereto.

FIG. 2 illustrates the structure of an LTE system according to an embodiment of the present disclosure. This may also be called an evolved UMTS terrestrial radio access network (E-UTRAN) or LTE/LTE-A system.

Referring to FIG. 2 , the E-UTRAN includes evolved Node Bs (eNBs) 20 which provide a control plane and a user plane to UEs 10. A UE 10 may be fixed or mobile, and may also be referred to as a mobile station (MS), user terminal (UT), subscriber station (SS), mobile terminal (MT), or wireless device. An eNB 20 is a fixed station communication with the UE 10 and may also be referred to as a base station (BS), a base transceiver system (BTS), or an access point.

eNBs 20 may be connected to each other via an X2 interface. An eNB 20 is connected to an evolved packet core (EPC) 39 via an S1 interface. More specifically, the eNB 20 is connected to a mobility management entity (MME) via an S1-MME interface and to a serving gateway (S-GW) via an S1-U interface.

The EPC 30 includes an MME, an S-GW, and a packet data network-gateway (P-GW). The MME has access information or capability information about UEs, which are mainly used for mobility management of the UEs. The S-GW is a gateway having the E-UTRAN as an end point, and the P-GW is a gateway having a packet data network (PDN) as an end point.

Based on the lowest three layers of the open system interconnection (OSI) reference model known in communication systems, the radio protocol stack between a UE and a network may be divided into Layer 1 (L1), Layer 2 (L2) and Layer 3 (L3). These layers are defined in pairs between a UE and an Evolved UTRAN (E-UTRAN), for data transmission via the Uu interface. The physical (PHY) layer at L1 provides an information transfer service on physical channels. The radio resource control (RRC) layer at L3 functions to control radio resources between the UE and the network. For this purpose, the RRC layer exchanges RRC messages between the UE and an eNB.

FIG. 3 illustrates the structure of an NR system

Referring to FIG. 3 , a next generation radio access network (NG-RAN) may include a next generation Node B (gNB) and/or an eNB, which provides user-plane and control-plane protocol termination to a UE. In FIG. 3 , the NG-RAN is shown as including only gNBs, by way of example. A gNB and an eNB are connected to each other via an Xn interface. The gNB and the eNB are connected to a 5G core network (5GC) via an NG interface. More specifically, the gNB and the eNB are connected to an access and mobility management function (AMF) via an NG-C interface and to a user plane function (UPF) via an NG-U interface.

FIG. 4 illustrates a radio frame structure in NR.

Referring to FIG. 4 , a radio frame may be used for UL transmission and DL transmission in NR. A radio frame is 10 ms in length, and may be defined by two 5-ms half-frames. An HF may include five 1-ms subframes. A subframe may be divided into one or more slots, and the number of slots in an SF may be determined according to a subcarrier spacing (SCS). Each slot may include 12 or 14 OFDM(A) symbols according to a cyclic prefix (CP).

In a normal CP (NCP) case, each slot may include 14 symbols, whereas in an extended CP (ECP) case, each slot may include 12 symbols. Herein, a symbol may be an OFDM symbol (or CP-OFDM symbol) or an SC-FDMA symbol (or DFT-s-OFDM symbol).

Table 1 below lists the number of symbols per slot N^(slot) _(symb), the number of slots per frame N^(frame,μ) _(slot), and the number of slots per subframe N^(subframe,μ) _(slot) according to an SCS configuration μ in the NCP case.

TABLE 1 SCS (15 * 2u) N^(slot) _(symb) N^(frame,u) _(slot) N^(subframe,u) _(slot)  15 KHz (u = 0) 14 10 1  30 KHz (u = 1) 14 20 2  60 KHz (u = 2) 14 40 4 120 KHz (u = 3) 14 80 8 240 KHz (u = 4) 14 160 16

Table 2 below lists the number of symbols per slot, the number of slots per frame, and the number of slots per subframe according to an SCS in the ECP case.

TABLE 2 SCS (15 * 2{circumflex over ( )}u) N^(slot) _(symb) N^(frame,u) _(slot) N^(subframe,u) _(slot) 60 KHz (u = 2) 12 40 4

In the NR system, different OFDM(A) numerologies (e.g., SCSs, CP lengths, and so on) may be configured for a plurality of cells aggregated for one UE. Accordingly, the (absolute time) duration of a time resource including the same number of symbols (e.g., a subframe, slot, or TTI) (collectively referred to as a time unit (TU) for convenience) may be configured to be different for the aggregated cells. In NR, various numerologies or SCSs may be supported to support various 5G services. For example, with an SCS of 15 kHz, a wide area in traditional cellular bands may be supported, while with an SCS of 30 kHz/60 kHz, a dense urban area, a lower latency, and a wide carrier bandwidth may be supported. With an SCS of 60 kHz or higher, a bandwidth larger than 24.25 GHz may be supported to overcome phase noise.

An NR frequency band may be defined by two types of frequency ranges, FR1 and FR2. The numerals in each frequency range may be changed. For example, the two types of frequency ranges may be given in [Table 3]. In the NR system, FR1 may be a “sub 6 GHz range” and FR2 may be an “above 6 GHz range” called millimeter wave (mmW).

TABLE 3 Frequency Range Corresponding Subcarrier designation frequency range Spacing (SCS) FR1   450 MHz-6000 MHz 15, 30, 60 kHz FR2 24250 MHz-52600 MHz 60, 120, 240 kHz

As mentioned above, the numerals in a frequency range may be changed in the NR system. For example, FR1 may range from 410 MHz to 7125 MHz as listed in [Table 4]. That is, FR1 may include a frequency band of 6 GHz (or 5850, 5900, and 5925 MHz) or above. For example, the frequency band of 6 GHz (or 5850, 5900, and 5925 MHz) or above may include an unlicensed band. The unlicensed band may be used for various purposes, for example, vehicle communication (e.g., autonomous driving).

TABLE 4 Frequency Corresponding Subcarrier Range designation frequency range Spacing (SCS) FR1  410 MHz-7125 MHz 15, 30, 60 kHz FR2 24250 MHz-52600 MHz 60, 120, 240 kHz

FIG. 5 illustrates a slot structure in an NR frame.

Referring to FIG. 5 , a slot includes a plurality of symbols in the time domain. For example, one slot may include 14 symbols in an NCP case and 12 symbols in an ECP case. Alternatively, one slot may include 7 symbols in an NCP case and 6 symbols in an ECP case.

A carrier includes a plurality of subcarriers in the frequency domain. An RB may be defined by a plurality of (e.g., 12) consecutive subcarriers in the frequency domain. A bandwidth part (BWP) may be defined by a plurality of consecutive (physical) RBs ((P)RBs) in the frequency domain and correspond to one numerology (e.g., SCS, CP length, or the like). A carrier may include up to N (e.g., 5) BWPs. Data communication may be conducted in an activated BWP. Each element may be referred to as a resource element (RE) in a resource grid, to which one complex symbol may be mapped.

A radio interface between UEs or a radio interface between a UE and a network may include L1, L2, and L3. In various embodiments of the present disclosure, L1 may refer to the PHY layer. For example, L2 may refer to at least one of the MAC layer, the RLC layer, the PDCH layer, or the SDAP layer. For example, L3 may refer to the RRC layer.

Now, a description will be given of sidelink (SL) communication.

FIG. 6 illustrates a radio protocol architecture for SL communication Specifically, FIG. 6(a) illustrates a user-plane protocol stack in LTE, and FIG. 6(b) illustrates a control-plane protocol stack in LTE.

Sidelink synchronization signals (SLSSs) and synchronization information will be described below.

The SLSSs, which are SL-specific sequences, may include a primary sidelink synchronization signal (PSSS) and a secondary sidelink synchronization signal (SSSS). The PSSS may be referred to as a sidelink primary synchronization signal (S-PSS), and the SSSS may be referred to as a sidelink secondary synchronization signal (S-SSS). For example, length-127 M-sequences may be used for the S-PSS, and length-127 gold-sequences may be used for the S-SSS. For example, the UE may detect an initial signal and acquire synchronization by using the S-PSS. For example, the UE may acquire fine synchronization and detect a synchronization signal ID, by using the S-PSS and the S-SSS.

A physical sidelink broadcast channel (PSBCH) may be a (broadcast) channel carrying basic (system) information that the UE needs to first know before transmitting and receiving an SL signal. For example, the basic information may include information related to the SLSSs, duplex mode (DM) information, time division duplex (TDD) UL/DL (UL/DL) configuration information, resource pool-related information, information about the type of an application related to the SLSSs, subframe offset information, broadcast information, and so on. For example, the payload size of the PSBCH may be 56 bits, including a 24-bit cyclic redundancy check (CRC), for evaluation of PSBCH performance in NR V2X.

The S-PSS, S-SSS, and PSBCH may be included in a block format (e.g., SL synchronization signal (SL SS)/PSBCH block, hereinafter, referred to as sidelink-synchronization signal block (S-SSB)) supporting periodic transmission. The S-SSB may have the same numerology (i.e., SCS and CP length) as a physical sidelink control channel (PSCCH)/physical sidelink shared channel (PSSCH) in a carrier, and the transmission bandwidth of the S-SSB may be within a (pre)configured SL BWP. For example, the bandwidth of the S-SSB may be 11 RBs. For example, the PSBCH may span 11 RBs. The frequency position of the S-SSB may be (pre)set. Therefore, the UE does not need to perform hypothesis detection in a frequency to discover the S-SSB in the carrier.

In the NR SL system, a plurality of numerologies including different SCSs and/or CP lengths may be supported. As an SCS increases, the length of a time resource for S-SSB transmission of a UE may be shortened. Accordingly, in order to ensure coverage of the S-SSB, a transmitting UE may transmit one or more S-SSBs to a receiving terminal within one S-SSB transmission period according to the SCS. For example, the number of S-SSBs that the transmitting terminal transmits to the receiving terminal within one S-SSB transmission period may be pre-configured or configured for the transmitting UE. For example, the S-SSB transmission period may be 160 ms. For example, for all SCSs, an S-SSB transmission period of 160 ms may be supported.

For example, when the SCS is 15 kHz in FR1, the transmitting UE may transmit one or two S-SSBs to the receiving UE within one S-SSB transmission period. For example, when the SCS is 30 kHz in FR1, the transmitting UE may transmit one or two S-SSBs to the receiving UE within one S-SSB transmission period. For example, when the SCS is 60 kHz in FR1, the transmitting UE may transmit one, two or four S-SSBs to the receiving UE within one S-SSB transmission period.

For example, when the SCS is 60 kHz in FR2, the transmitting UE may transmit 1, 2, 4, 8, 16, or 32 S-SSBs to the receiving UE within one S-SSB transmission period. For example, when the SCS is 120 kHz in FR2, the transmitting UE may transmit 1, 2, 4, 8, 16, 32, or 64 S-SSBs to the receiving UE within one S-SSB transmission period.

When the SCS is 60 kHz, two types of CPs may be supported. Further, the structure of an S-SSB transmitted by the transmitting UE to the receiving UE may be different according to a CP type. For example, the CP type may be an NCP or an ECP. Specifically, for example, when the CP type is NCP, the number of symbols to which the PSBCH is mapped in the S-SSB transmitted by the transmitting UE may be 9 or 8. On the other hand, for example, when the CP type is ECP, the number of symbols to which the PSBCH is mapped in the S-SSB transmitted by the transmitting UE may be 7 or 6. For example, the PSBCH may be mapped to the first symbol of the S-SSB transmitted by the transmitting UE. For example, upon receipt of the S-SSB, the receiving UE may perform an automatic gain control (AGC) operation in the first symbol period of the S-SSB.

FIG. 7 illustrates UEs that conduct V2X or SL communication between them.

Referring to FIG. 7 , the term “UE” in V2X or SL communication may mainly refer to a terminal of a user. However, when network equipment such as a BS transmits and receives a signal according to a UE-to-UE communication scheme, the BS may also be regarded as a kind of UE. For example, a first UE (UE1) may be a first device 100 and a second UE (UE2) may be a second device 200.

For example, UE1 may select a resource unit corresponding to specific resources in a resource pool which is a set of resources. UE1 may then transmit an SL signal in the resource unit. For example, UE2, which is a receiving UE, may be configured with the resource pool in which UE1 may transmit a signal, and detect the signal from UE1 in the resource pool.

When UE1 is within the coverage of the BS, the BS may indicate the resource pool to UE1. On the contrary, when UE1 is outside the coverage of the BS, another UE may indicate the resource pool to UE1, or UE1 may use a predetermined resource pool.

In general, a resource pool may include a plurality of resource units, and each UE may select one or more resource units and transmit an SL signal in the selected resource units.

FIG. 8 illustrates resource units for V2X or SL communication.

Referring to FIG. 8 , the total frequency resources of a resource pool may be divided into NF frequency resources, and the total time resources of the resource pool may be divided into NT time resources. Thus, a total of NF*NT resource units may be defined in the resource pool. FIG. 13 illustrates an example in which the resource pool is repeated with a periodicity of NT subframes.

As illustrates in FIG. 8 , one resource unit (e.g., Unit #0) may appear repeatedly with a periodicity. Alternatively, to achieve a diversity effect in the time or frequency domain, the index of a physical resource unit to which one logical resource unit is mapped may change over time in a predetermined pattern. In the resource unit structure, a resource pool may refer to a set of resource units available to a UE for transmission of an SL signal.

Resource pools may be divided into several types. For example, each resource pool may be classified as follows according to the content of an SL signal transmitted in the resource pool.

(1) A scheduling assignment (SA) may be a signal including information about the position of resources used for a transmitting UE to transmit an SL data channel, a modulation and coding scheme (MCS) or multiple input multiple output (MIMO) transmission scheme required for data channel demodulation, a timing advertisement (TA), and so on. The SA may be multiplexed with the SL data in the same resource unit, for transmission. In this case, an SA resource pool may refer to a resource pool in which an SA is multiplexed with SL data, for transmission. The SA may be referred to as an SL control channel.

(2) An SL data channel (PSSCH) may be a resource pool used for a transmitting UE to transmit user data. When an SA is multiplexed with SL data in the same resource unit, for transmission, only the SL data channel except for SA information may be transmitted in a resource pool for the SL data channel. In other words, REs used to transmit the SA information in an individual resource unit in an SA resource pool may still be used to transmit SL data in the resource pool of the SL data channel. For example, the transmitting UE may transmit the PSSCH by mapping the PSSCH to consecutive PRBs.

(3) A discovery channel may be a resource pool used for a transmitting UE to transmit information such as its ID. The transmitting UE may enable a neighboring UE to discover itself on the discovery channel.

Even when SL signals have the same contents as described above, different resource pools may be used according to the transmission/reception properties of the SL signals. For example, in spite of the same SL data channel or discovery message, a different resources pool may be used for an SL signal according to a transmission timing determination scheme for the SL signal (e.g., whether the SL signal is transmitted at a reception time of a synchronization reference signal (RS) or at a time resulting from applying a predetermined TA to the reception time), a resource allocation scheme for the SL signal (e.g., whether a BS allocates transmission resources of an individual signal to an individual transmitting UE or whether the individual transmitting UE selects its own individual signal transmission resources in the resource pool), the signal format of the SL signal (e.g., the number of symbols occupied by each SL signal in one subframe, or the number of subframes used for transmission of one SL signal), the strength of a signal from the BS, the transmission power of the SL UE, and so on.

Resource allocation in SL will be described below.

FIG. 9 illustrates a procedure of performing V2X or SL communication according to a transmission mode in a UE according to an embodiment of the present disclosure. In various embodiments of the present disclosure, a transmission mode may also be referred to as a mode or a resource allocation mode. For the convenience of description, a transmission mode in LTE may be referred to as an LTE transmission mode, and a transmission mode in NR may be referred to as an NR resource allocation mode.

For example, FIG. 9 (a) illustrates a UE operation related to LTE transmission mode 1 or LTE transmission mode 3. Alternatively, for example, FIG. 9 (a) illustrates a UE operation related to NR resource allocation mode 1. For example, LTE transmission mode 1 may be applied to general SL communication, and LTE transmission mode 3 may be applied to V2X communication.

For example, FIG. 9 (b) illustrates a UE operation related to LTE transmission mode 2 or LTE transmission mode 4. Alternatively, for example, FIG. 9 (b) illustrates a UE operation related to NR resource allocation mode 2.

Referring to FIG. 9 (a), in LTE transmission mode 1, LTE transmission mode 3, or NR resource allocation mode 1, a BS may schedule SL resources to be used for SL transmission of a UE. For example, the BS may perform resource scheduling for UE1 through a PDCCH (more specifically, DL control information (DCI)), and UE1 may perform V2X or SL communication with UE2 according to the resource scheduling. For example, UE1 may transmit sidelink control information (SCI) to UE2 on a PSCCH, and then transmit data based on the SCI to UE2 on a PSSCH.

For example, in NR resource allocation mode 1, a UE may be provided with or allocated resources for one or more SL transmissions of one transport block (TB) by a dynamic grant from the BS. For example, the BS may provide the UE with resources for transmission of a PSCCH and/or a PSSCH by the dynamic grant. For example, a transmitting UE may report an SL hybrid automatic repeat request (SL HARQ) feedback received from a receiving UE to the BS. In this case, PUCCH resources and a timing for reporting the SL HARQ feedback to the BS may be determined based on an indication in a PDCCH, by which the BS allocates resources for SL transmission.

For example, the DCI may indicate a slot offset between the DCI reception and a first SL transmission scheduled by the DCI. For example, a minimum gap between the DCI that schedules the SL transmission resources and the resources of the first scheduled SL transmission may not be smaller than a processing time of the UE.

For example, in NR resource allocation mode 1, the UE may be periodically provided with or allocated a resource set for a plurality of SL transmissions through a configured grant from the BS. For example, the grant to be configured may include configured grant type 1 or configured grant type 2. For example, the UE may determine a TB to be transmitted in each occasion indicated by a given configured grant.

For example, the BS may allocate SL resources to the UE in the same carrier or different carriers.

For example, an NR gNB may control LTE-based SL communication. For example, the NR gNB may transmit NR DCI to the UE to schedule LTE SL resources. In this case, for example, a new RNTI may be defined to scramble the NR DCI. For example, the UE may include an NR SL module and an LTE SL module.

For example, after the UE including the NR SL module and the LTE SL module receives NR SL DCI from the gNB, the NR SL module may convert the NR SL DCI into LTE DCI type 5A, and transmit LTE DCI type 5A to the LTE SL module every Xms. For example, after the LTE SL module receives LTE DCI format 5A from the NR SL module, the LTE SL module may activate and/or release a first LTE subframe after Z ms. For example, X may be dynamically indicated by a field of the DCI. For example, a minimum value of X may be different according to a UE capability. For example, the UE may report a single value according to its UE capability. For example, X may be positive.

Referring to FIG. 9 (b), in LTE transmission mode 2, LTE transmission mode 4, or NR resource allocation mode 2, the UE may determine SL transmission resources from among SL resources preconfigured or configured by the BS/network. For example, the preconfigured or configured SL resources may be a resource pool. For example, the UE may autonomously select or schedule SL transmission resources. For example, the UE may select resources in a configured resource pool on its own and perform SL communication in the selected resources. For example, the UE may select resources within a selection window on its own by a sensing and resource (re)selection procedure. For example, the sensing may be performed on a subchannel basis. UE1, which has autonomously selected resources in a resource pool, may transmit SCI to UE2 on a PSCCH and then transmit data based on the SCI to UE2 on a PSSCH.

For example, a UE may help another UE with SL resource selection. For example, in NR resource allocation mode 2, the UE may be configured with a grant configured for SL transmission. For example, in NR resource allocation mode 2, the UE may schedule SL transmission for another UE. For example, in NR resource allocation mode 2, the UE may reserve SL resources for blind retransmission.

For example, in NR resource allocation mode 2, UE1 may indicate the priority of SL transmission to UE2 by SCI. For example, UE2 may decode the SCI and perform sensing and/or resource (re)selection based on the priority. For example, the resource (re)selection procedure may include identifying candidate resources in a resource selection window by UE2 and selecting resources for (re)transmission from among the identified candidate resources by UE2. For example, the resource selection window may be a time interval during which the UE selects resources for SL transmission. For example, after UE2 triggers resource (re)selection, the resource selection window may start at T1≥0, and may be limited by the remaining packet delay budget of UE2. For example, when specific resources are indicated by the SCI received from UE1 by the second UE and an L1 SL reference signal received power (RSRP) measurement of the specific resources exceeds an SL RSRP threshold in the step of identifying candidate resources in the resource selection window by UE2, UE2 may not determine the specific resources as candidate resources. For example, the SL RSRP threshold may be determined based on the priority of SL transmission indicated by the SCI received from UE1 by UE2 and the priority of SL transmission in the resources selected by UE2.

For example, the L1 SL RSRP may be measured based on an SL demodulation reference signal (DMRS). For example, one or more PSSCH DMRS patterns may be configured or preconfigured in the time domain for each resource pool. For example, PDSCH DMRS configuration type 1 and/or type 2 may be identical or similar to a PSSCH DMRS pattern in the frequency domain. For example, an accurate DMRS pattern may be indicated by the SCI. For example, in NR resource allocation mode 2, the transmitting UE may select a specific DMRS pattern from among DMRS patterns configured or preconfigured for the resource pool.

For example, in NR resource allocation mode 2, the transmitting UE may perform initial transmission of a TB without reservation based on the sensing and resource (re)selection procedure. For example, the transmitting UE may reserve SL resources for initial transmission of a second TB using SCI associated with a first TB based on the sensing and resource (re)selection procedure.

For example, in NR resource allocation mode 2, the UE may reserve resources for feedback-based PSSCH retransmission through signaling related to a previous transmission of the same TB. For example, the maximum number of SL resources reserved for one transmission, including a current transmission, may be 2, 3 or 4. For example, the maximum number of SL resources may be the same regardless of whether HARQ feedback is enabled. For example, the maximum number of HARQ (re)transmissions for one TB may be limited by a configuration or preconfiguration. For example, the maximum number of HARQ (re)transmissions may be up to 32. For example, if there is no configuration or preconfiguration, the maximum number of HARQ (re)transmissions may not be specified. For example, the configuration or preconfiguration may be for the transmitting UE. For example, in NR resource allocation mode 2, HARQ feedback for releasing resources which are not used by the UE may be supported.

For example, in NR resource allocation mode 2, the UE may indicate one or more subchannels and/or slots used by the UE to another UE by SCI. For example, the UE may indicate one or more subchannels and/or slots reserved for PSSCH (re)transmission by the UE to another UE by SCI. For example, a minimum allocation unit of SL resources may be a slot. For example, the size of a subchannel may be configured or preconfigured for the UE.

SCI will be described below.

While control information transmitted from a BS to a UE on a PDCCH is referred to as DCI, control information transmitted from one UE to another UE on a PSCCH may be referred to as SCI. For example, the UE may know the starting symbol of the PSCCH and/or the number of symbols in the PSCCH before decoding the PSCCH. For example, the SCI may include SL scheduling information. For example, the UE may transmit at least one SCI to another UE to schedule the PSSCH. For example, one or more SCI formats may be defined.

For example, the transmitting UE may transmit the SCI to the receiving UE on the PSCCH. The receiving UE may decode one SCI to receive the PSSCH from the transmitting UE.

For example, the transmitting UE may transmit two consecutive SCIs (e.g., 2-stage SCI) on the PSCCH and/or PSSCH to the receiving UE. The receiving UE may decode the two consecutive SCIs (e.g., 2-stage SCI) to receive the PSSCH from the transmitting UE. For example, when SCI configuration fields are divided into two groups in consideration of a (relatively) large SCI payload size, SCI including a first SCI configuration field group is referred to as first SCI. SCI including a second SCI configuration field group may be referred to as second SCI. For example, the transmitting UE may transmit the first SCI to the receiving UE on the PSCCH. For example, the transmitting UE may transmit the second SCI to the receiving UE on the PSCCH and/or PSSCH. For example, the second SCI may be transmitted to the receiving UE on an (independent) PSCCH or on a PSSCH in which the second SCI is piggybacked to data. For example, the two consecutive SCIs may be applied to different transmissions (e.g., unicast, broadcast, or groupcast).

For example, the transmitting UE may transmit all or part of the following information to the receiving UE by SCI. For example, the transmitting UE may transmit all or part of the following information to the receiving UE by first SCI and/or second SCI.

PSSCH-related and/or PSCCH-related resource allocation information, for example, the positions/number of time/frequency resources, resource reservation information (e.g. a periodicity), and/or

an SL channel state information (CSI) report request indicator or SL (L1) RSRP (and/or SL (L1) reference signal received quality (RSRQ) and/or SL (L1) received signal strength indicator (RSSI)) report request indicator, and/or

an SL CSI transmission indicator (on PSSCH) (or SL (L1) RSRP (and/or SL (L1) RSRQ and/or SL (L1) RSSI) information transmission indicator), and/or

MCS information, and/or

transmission power information, and/or

L1 destination ID information and/or L1 source ID information, and/or

SL HARQ process ID information, and/or

new data indicator (NDI) information, and/or

redundancy version (RV) information, and/or

QoS information (related to transmission traffic/packet), for example, priority information, and/or

An SL CSI-RS transmission indicator or information about the number of SL CSI-RS antenna ports (to be transmitted);

Location information about a transmitting UE or location (or distance area) information about a target receiving UE (requested to transmit an SL HARQ feedback), and/or

RS (e.g., DMRS or the like) information related to decoding and/or channel estimation of data transmitted on a PSSCH, for example, information related to a pattern of (time-frequency) mapping resources of the DMRS, rank information, and antenna port index information.

For example, the first SCI may include information related to channel sensing. For example, the receiving UE may decode the second SCI using the PSSCH DMRS. A polar code used for the PDCCH may be applied to the second SCI. For example, the payload size of the first SCI may be equal for unicast, groupcast and broadcast in a resource pool. After decoding the first SCI, the receiving UE does not need to perform blind decoding on the second SCI. For example, the first SCI may include scheduling information about the second SCI.

In various embodiments of the present disclosure, since the transmitting UE may transmit at least one of the SCI, the first SCI, or the second SCI to the receiving UE on the PSCCH, the PSCCH may be replaced with at least one of the SCI, the first SCI, or the second SC. Additionally or alternatively, for example, the SCI may be replaced with at least one of the PSCCH, the first SCI, or the second SCI. Additionally or alternatively, for example, since the transmitting UE may transmit the second SCI to the receiving UE on the PSSCH, the PSSCH may be replaced with the second SCI.

Hereinafter, acquisition of synchronization of a SL UE will be described.

In time division multiple access (TDMA) and frequency division multiples access (FDMA) systems, accurate time and frequency synchronization may be required. When the time and frequency synchronization are not accurate, system performance may be degraded due to inter symbol interference (ISI) and inter carrier interference (ICI). This is also applied to V2X in the same way. In V2X, for time/frequency synchronization, a sidelink (SL) synchronization signal (SLSS) may be used in physical layer, and a master information block-sidelink-V2X (MIB-SL-V2X) may be used in a radio link control (RLC) layer.

Tx/Rx Beam Sweep

When a very high frequency is used as in mmWave, beamforming may be generally used to overcome high pathloss. In order to use beamforming, first, the best beam pair needs to be detected among several beam pairs between a transmitting end and a receiving end. This process may be referred to as beam acquisition or beam tracking or beam tracking in terms of the receiving end. In particular, in mmWave, analog beamforming is used, and thus a vehicle needs to perform beam sweeping for switching beams in different directions at different times using an antenna array of the vehicle itself during the beam acquisition or the beam tracking.

Multiple Active Sidelink BWPs

In NR V2X, communication through support of a plurality of BWPs (i.e., support of a plurality of configured sidelink BWPs and/or support of a plurality of active sidelink BWPs) may be considered. This may be for supporting different numerologies or heterogeneous services/communications that require parameters and/or requirements or may also be for ICI reduction due to a reduced CP length.

FIG. 10 illustrates an exemplary architecture of a 5G system capable of positioning a UE connected to an NG-RAN or an E-UTRAN according to an embodiment of the present disclosure.

Referring to FIG. 10 , an AMF may receive a request for a location service related to a specific target UE from another entity such as a gateway mobile location center (GMLC) or may autonomously determine to initiate the location service on behalf of the specific target UE. The AMF may then transmit a location service request to a location management function (LMF). Upon receipt of the location service request, the LMF may process the location service request and return a processing result including information about an estimated location of the UE to the AMF. On the other hand, when the location service request is received from another entity such as the GMLC, the AMF may deliver the processing result received from the LMF to the other entity.

Anew generation evolved-NB (ng-eNB) and a gNB, which are network elements of an NG-RAN capable of providing measurement results for positioning, may measure radio signals for the target UE and transmit result values to the LMF. The ng-eNB may also control some transmission points (TPs) such as remote radio heads or positioning reference signal (PRS)-dedicated TPs supporting a PRS-based beacon system for an E-UTRA.

The LMF is connected to an enhanced serving mobile location center (E-SMLC), and the E-SMLC may enable the LMF to access an E-UTRAN. For example, the E-SMLC may enable the LMF to support observed time difference of arrival (OTDoA), which is one of positioning methods in the E-UTRAN, by using DL measurements obtained by the target UE through signals transmitted by the eNB and/or the PRS-dedicated TPs in the E-UTRAN.

The LMF may be connected to an SUPL location platform (SLP). The LMF may support and manage different location determination services for target UEs. The LMF may interact with the serving ng-eNB or serving gNB of a target UE to obtain a location measurement of the UE. For positioning the target UE, the LMF may determine a positioning method based on a location service (LCS) client type, a QoS requirement, UE positioning capabilities, gNB positioning capabilities, and ng-eNB positioning capabilities, and apply the positioning method to the serving gNB and/or the serving ng-eNB. The LMF may determine additional information such as a location estimate for the target UE and the accuracy of the position estimation and a speed. The SLP is a secure user plane location (SUPL) entity responsible for positioning through the user plane.

The UE may measure a DL signal through sources such as the NG-RAN and E-UTRAN, different global navigation satellite systems (GNSSes), a terrestrial beacon system (TBS), a wireless local area network (WLAN) access point, a Bluetooth beacon, and a UE barometric pressure sensor. The UE may include an LCS application and access the LCS application through communication with a network to which the UE is connected or through another application included in the UE. The LCS application may include a measurement and calculation function required to determine the location of the UE. For example, the UE may include an independent positioning function such as a global positioning system (GPS) and report the location of the UE independently of an NG-RAN transmission. The independently obtained positioning information may be utilized as auxiliary information of positioning information obtained from the network.

FIG. 11 illustrates exemplary implementation of a network for positioning a UE according to an embodiment of the present disclosure.

Upon receipt of a location service request when the UE is in a connection management-IDLE (CM-IDLE) state, the AMF may establish a signaling connection with the UE and request a network trigger service to assign a specific serving gNB or ng-eNB. This operation is not shown in FIG. 11 . That is, FIG. 11 may be based on the assumption that the UE is in connected mode. However, the signaling connection may be released by the NG-RAN due to signaling and data deactivation during positioning.

Referring to FIG. 11 , a network operation for positioning a UE will be described in detail. In step 1 a, a 5GC entity such as a GMLC may request a location service for positioning a target UE to a serving AMF. However, even though the GMLC does not request the location service, the serving AMF may determine that the location service for positioning the target UE is required in step 1 b. For example, for positioning the UE for an emergency call, the serving AMF may determine to perform the location service directly.

The AMF may then transmit a location service request to an LMF in step 2, and the LMF may start location procedures with the serving-eNB and the serving gNB to obtain positioning data or positioning assistance data in step 3 a. Additionally, the LMF may initiate a location procedure for DL positioning with the UE in step 3 b. For example, the LMF may transmit positioning assistance data (assistance data defined in 3GPP TS 36.355) to the UE, or obtain a location estimate or location measurement. Although step 3 b may be additionally performed after step 3 a, step 3 b may be performed instead of step 3 a.

In step 4, the LMF may provide a location service response to the AMF. The location service response may include information indicating whether location estimation of the UE was successful and the location estimate of the UE. Then, when the procedure of FIG. 11 is initiated in step 1 a, the AMF may deliver the location service response to the 5GC entity such as the GMLC. When the procedure of FIG. 11 is initiated in step 1 b, the AMF may use the location service response to provide the location service related to an emergency call or the like.

Hereinafter, a Hybrid Automatic Repeat Request (HARQ) procedure in a sidelink will be described.

An error compensation scheme for ensuring communication reliability may include a Forward Error Correction (FEC) scheme and an Automatic Repeat Request (ARQ) scheme. In the FEC scheme, error at a reception end may be corrected by adding an extra error correction code to information bits. The FEC scheme is advantageous in that time delay is low and information that is separately transmitted and received between transmission and reception ends is not required, but is disadvantageous in that system efficiency is degraded in a fine channel environment. The ARQ scheme has high transmission reliability, but is disadvantageous in that time delay occurs and system efficiency is degraded in a poor channel environment.

The Hybrid Automatic Repeat Request (HARQ) scheme is obtained by combining the FEC and the ARQ, and in this case, performance may be improving performance by checking whether data received by a physical layer contains error that is not capable of being decoded and requesting retransmission when error occurs.

In the case of SL unicast and groupcast, HARQ feedback and HARQ combining at a physical layer may be supported. For example, when a reception UE operates in a resource allocation mode 1 or 2, the reception UE may receive a PSSCH from a transmission UE, and the reception UE may transmit HARQ feedback with respect to the PSSCH to the transmission UE using a Sidelink Feedback Control Information (SFCI) format through a physical sidelink feedback channel (PSFCH).

For example, the SL HARQ feedback may be enabled for unicast. In this case, in a non-Code Block Group (non-CBG) operation, the reception UE may decode the PSCCH with the reception UE as a target, and when the reception UE successfully decodes a transmission block related to the PSCCH, the reception UE may generate an HARQ-ACK. The reception UE may transmit the HARQ-ACK to the transmission UE. In contrast, when the reception UE decodes the PSCCH with the reception UE as a target and then does not successfully decode the transmission block related to the PSCCH, the reception UE may generate the HARQ-NACK. The reception UE may transmit the HARQ-NACK to the transmission UE.

When sidelink HARQ feedback is enabled for groupcast, the UE may determine whether to transmit HARQ feedback based on a TX-RX distance and/or RSRP. In the case of a non-CBG operation, two options may be supported.

(1) Option 1: When a reception UE fails to decode a corresponding transport block after decoding a PSCCH associated to the reception UE, the reception UE may transmit HARQ-NACK on a PSFCH. Otherwise, the reception UE may not transmit a signal on the PSFCH.

(2) Option 2: When the reception UE successfully decodes the transport block, the reception UE may transmit HARQ-ACK on the PSFCH. After the reception UE decodes an associated PSCCH using the reception UE as a target, if the reception UE does not successfully decode the corresponding transport block, the reception UE may transmit HARQ-NACK on the PSFCH.

In the case of mode 1 resource allocation, a time between HARQ feedback transmission on the PSFCH and the PSSCH may be (pre)configured. In the case of unicast and groupcast, when retransmission on sidelink is required, this may be indicated to an eNB by a UE within coverage using the PUCCH. The transmission UE may also transmit indication to a serving eNB of the transmission UE in the form of scheduling request (SR)/buffer status report (BSR) but not the form of HARQ ACK/NACK. Even if the eNB does not receive the indication, the eNB may schedule a sidelink retransmission resource to the UE.

In the case of mode 2 resource allocation, a time between HARQ feedback transmission on the PSFCH and the PSSCH may be (pre)configured.

Embodiment

The present embodiment relates to a technology of transmitting a positioning reference signal (PRS) for sidelink positioning through a physical sidelink feedback channel (PSFCH) in an NR-V2X system and proposes a PRS transmission method using a PRS transmission structure preconfigured on the PSFCH and the PSFCH in order to effectively use a PSFCH-PRS resource (a PSFCH resource for PRS).

For pre-configuration of the PSFCH-PRS, on-demand positioning may be considered, and 1) a transmission structure between a request PRS and a response PRS, 2) a time gap between a request PRS transmission time and a response PRS reception time (request PRS-response PRS time gap), 3) PRS ID allocation for request PRS and response PRS transmission, and the like may be mainly considered. Furthermore, the present embodiment proposes a procedure of performing on-demand positioning and broadcast positioning in terms of PRS transmission. Hereinafter, terms used in a positioning reference signal (PRS) transmission technology for sidelink positioning through a PSFCH in the NR-V2X system according to the present embodiment will be described in detail.

-   -   Data may include message information, voice/image information,         sensor information, position information, and the like.     -   A UE may include a mobile device, a V2X module, and an IoT         device, and the anchor node (AN) may be an eNB and/or a UE. In         this case, an eNB as the AN may include eNB, gNB, LTE-LAA, NR-U,         transmission point (TP), Remote Head Control (RHC), gNB-type         road-side unit (RSU), and UE-type RSU, which provides fixed (or         absolute) position information, and a UE as the AN may include a         UE for providing position information with high reliability and         a UE-type RSU for providing fixed position information.     -   A resource for positioning may include a resource for sidelink         positioning control information (SPCI) indicating positioning         control information and a PSFCH-PRS resource for PRS         transmission as follows.

The SPCI may be transmitted in a system information block (SIB) of a phsycal sidelink broadcast channel (PSBCH) and 1^(st)-stage sidelink control information (SCI) of a physical sidelink control channel (PSCCH) and/or a 2^(nd)-stage SCI resource of a PSSCH. In this case, the SPCI may mainly include at least one of PSFCH configuration information for PRS transmission, various pieces of measurement information related to positioning, PSFCH-PRS resource information for PRS transmission, or PRS ID reservation information.

The PSFCH-PRS resource may refer to a resource allocated for PRS transmission along all resources allocated to the PSFCH. According to an embodiment, when a PRS and HARQ-ACK feedback information are transmitted on the PSFCH, the PSFCH-PRS resource may refer to all or some resources except for the PSFCH-feedback resource for HARQ-ACK feedback information transmission.

A PRS transmitted through the PSFCH-PRS resource may have a unique PRS ID, and in this case, each PRS ID may have the time domain and the frequency domain of the PSFCH-PRS resource and/or mutual orthogonality in a code division multiplexing (CDM) region.

The sidelink positioning may include on-demand positioning and broadcast positioning.

A PRS for the on-demand positioning may include a request PRS and a response PRS. In contrast, a PRS for the broadcast positioning may include only a unidirectional PRS.

A V2X data slot may refer to a slot reserved to transmit V2X data.

Hereinafter, an on-demand positioning method and a broadcast positioning method for sidelink positioning in an NR-V2X system will be described in detail.

A PSFCH-PRS resource for effectively using a resource when sidelink on-demand positioning is performed may be pre-configured.

Hereinafter, with reference to the drawings, a PRS transmission structure obtained by pre-configuring the sidelink on-demand positioning, a corresponding structure related rule, and a PRS transmission method will be described.

FIG. 12 is a diagram for explaining a pre-configuration PRS transmission method for sidelink on-demand positioning according to an embodiment.

Referring to FIG. 12 , the pre-configuration PRS transmission method may be broadly classified into a request PRS and response PRS transmission method using the same PSFCH-PRS resource (FIG. 12(a)), a request PRS and response PRS transmission method using different PSFCH-PRS resources (FIG. 12(b)), and a request PRS and response PRS transmission method using different PSFCH-PRS group resources (FIG. 12(c)).

A PSFCH transmission resource may be allocated to a specific symbol within a specific logical slot of a specific subchannel. For example, the PSFCH transmission resource may be allocated to the last two symbols of a corresponding slot, and a frequency resource for PSFCH transmission may be indicated by a bitmap for resource blocks (RBs) within a corresponding resource pool. A resource for ACK and a resource for NACK in each PSFCH may be allocated to different subchannels. SFCI transmitted by a PSFCH may be a sequence based signal. For example, 1-bit ACK/NACK may be distinguished through different cyclic shifts of the same base sequence. The PSCCH, the PSSCH, and the PSFCH may be multiplexed and transmitted in the time domain of the same slot. In this case, the PSCCH and the PSSCH may be multiplexed in the time domain and the frequency domain.

As seen from FIG. 12(a), different UEs may transmit a request PRS or may transmit a response PRS using the same PSFCH-PRS resource. In this case, a request PRS ID for transmission of a request PRS and a response PRS ID for transmission of a response PRS may be selected from PRS ID sets or pools defined in the same PSFCH-PRS resource.

Referring to FIG. 12(b), a PSFCH-PRS resource for transmission of a request PRS and a PSFCH-PRS resource for transmission of a response PRS may be allocated to different slots and may be alternately transmitted. In this case, the request PRS and the response PRS may be pre-configured to be transmitted through only a corresponding PSFCH-PRS resource. Here, the request PRS ID for transmission of the request PRS and the response PRS ID for transmission of the response PRS may be selected from PRS ID sets or pools defined in different PSFCH-PRS resources.

As seen from FIG. 12(c), a PSFCH-PRS group resource for transmission of a request PRS and a PSFCH-PRS group resource for transmission of a response PRS may be arranged and may be alternately allocated in different slots. In this case, the request PRS and the response PRS may be transmitted through only a corresponding PSFCH-PRS group resource.

According to an embodiment, in FIG. 12(c), a PSFCH-PRS group may include one or more PSFCH-PRS resources, and respective PSFCH-PRS resources in a PSFCH-PRS group may be used for PRS transmission of different types (request or response) of PRS transmission. According to another embodiment, respective PSFCH-PRS resources in a PSFCH-PRS group may also be used to be repeatedly transmitted the same type PRS. According to another embodiment, respective PSFCH-PRS resources in a PSFCH-PRS group may also be used to transmit an associated PRS like in the case in which the same type PRS is transmitted through frequency hopping.

Referring to FIG. 12 , a time gap between a request PRS transmission time and a response PRS transmission time related to the corresponding request RRS (request PRS-response PRS time gap, n) may be predefined and preconfigured.

For example, referring to FIG. 12(a), in the case of n=2, a UE (or gNB/UE-type RSU), i.e., a neighbor UE, which receives a request PRS transmitted from one UE (or gNB/UE-type RSU), i.e., a positioning UE, may transmit a response PRS related to the corresponding request PRS when 2 slots elapse from a time point of transmitting the corresponding request PRS.

In contrast, as shown in FIG. 12(b), in the case of n=3, a neighbor UE that receives a request PRS transmitted from a positioning UE may transmit a response PRS related to the corresponding request PRS when 3 slots elapse from a time point of transmitting the corresponding request PRS.

Hereinafter, a PRS ID allocation method for pre-configured PRS transmission will be described.

Sidelink on-demand positioning according to an embodiment may broadly include 1:1 on-demand positioning and 1:N on-demand positioning.

In the 1:1 on-demand positioning, PRS IDs of the request PRS and response PRS may be predefined, mapped, or paired and may be transmitted as follows during positioning between one UE and another UE or between one UE and one RSU similarly to a unicast mode (or in the case of a unicast mode).

-   -   Method of transmitting a request PRS and a response PRS using         the same PRS ID: A request PRS ID for transmitting the request         PRS and a response PRS ID for transmitting the response PRS may         be configured to be the same. As a result, a UE that receives         the request PRS may check the request PRS ID and may then         transmit the response PRS using the same response PRS ID as the         checked request PRS ID.     -   Method of transmitting a request PRS and a response PRS using         different PRS IDs: A PRS ID used to transmit the request PRS and         a PRS ID used for the response PRS transmitted in response to         the corresponding request PRS may be different from each other.         In this case, a relationship between the PRS ID of the request         PRS and the PRS ID of the response PRS related to the request         PRS may be configured by being pre-mapped or paired. For         example, when (request) PRS ID-0 for transmission of the request         PRS and (response) PRS ID-3 for the response PRS transmitted in         response to the request PRS are configured by being pre-mapped,         a UE that receives the request PRS may transmit the response PRS         using PRS ID-3 in response to the request PRS when the request         PRS ID is PRS ID-0.

In the 1:N on-demand positioning, the request PRS and the response PRS may be transmitted as follows during positioning between one UE and N other UEs or one UE and N RSUs similarly to a groupcast mode (or in the case of the groupcast mode).

-   -   Method of transmitting a request PRS and a response PRS through         pre-mapping or pairing: The 1:N on-demand positioning may be         performed by sequentially performing the 1:1 on-demand         positioning N times, and as a result, the request PRS and         response PRS transmission method through pre-mapping or pairing         described above in the 1:1 on-demand positioning may be used.     -   Request PRS and response PRS transmission method through group         pre-mapping: N response PRS ID groups in response to one request         PRS ID may be group-mapped in advance and may be defined. In         this case, N response PRS ID groups may be predefined or may be         determined by a location server/LMF and/or an eNB. In addition,         a response PRS ID used as a response by each UE receiving the         request PRS may be determined in consideration of an ID of a UE         transmitting the request PRS, an ID of a UE receiving the source         ID and/or request PRS, or a destination ID. For example, when         (request) PRS ID-0 for transmission of the request PRS and three         IDs including (response) PRS ID-0, PRS ID-1, and PRS ID-2 for         the response PRS transmitted in response to the request PRS are         group-mapped in advance and are configured, three UEs receiving         the request PRS may select and use any one of PRS ID-0, PRS         ID-1, and PRS ID-2 and may transmit the response PRS in response         to the request PRS when the request PRS ID is PRS ID-0. The         response PRS ID used in response to the request PRS by each UE         receiving the request PRS may be determined in consideration of         a ID of a UE transmitting the request PRS, an ID receiving the         source ID and/or the request PRS, or a destination ID.

Hereinafter, an on-demand positioning procedure and a broadcast positioning procedure in terms of PRS transmission for sidelink positioning will be described. In this case, resource reservation for PRS transmission may be performed through a slot reservation process for V2X data. In contrast, when a PSFCH-PRS resource for PRS transmission is preconfigured or reserved, PRS transmission may be performed in a slot for V2X data transmission or may be performed in a different slot from the slot for V2X data transmission.

FIG. 13 is a flowchart for explaining a sidelink on-demand positioning procedure in a positioning UE according to an embodiment.

Referring to FIG. 13 , the positioning UE may reserve a slot for V2X data transmission and may simultaneously reserve a PSFCH-PRS resource and PRS ID for request PRS transmission (S1310).

In this case, PSFCH-PRS resource reservation may include an operation of determining and reserving a logical slot, a PSFCH-PRS resource of which is used to transmit the request PRS by the positioning UE, when there is a request for PRS transmission resource reservation for performing positioning from a higher layer.

The positioning UE may determine and reserve a PSFCH-PRS resource for request PRS transmission and may then determine and reserve a PRS ID used to transmit the request PRS.

The PSFCH-PRS resource reservation process and the PRS ID reservation process in the positioning UE may be sequentially or simultaneously performed, and the PSFCH-PRS resource reservation information and reservation information for the PRS ID may be included in SCI of a PSCCH and/or a PSSCH and may be transmitted to a neighbor UE. In detail, SPCI including the PSFCH-PRS resource reservation information and the reservation information for the PRS ID may be included in 1^(st)-stage SCI of the PSCCH and/or 2^(nd)-stage SCI of the PSSCH and may be transmitted.

In the case of NR-V2X mode-1, a PSFCH-PRS resource and a PRS ID to be reserved by the positioning UE may be detected by an eNB.

In the case of NR-V2X mode-2, a PSFCH-PRS resource and a PRS ID to be reserved by the positioning UE may be detected through a process of analyzing 1^(st)-stage SCI of the PSCCH and/or 2^(nd)-stage SCI of the PSSCH, which are received (or sensed) from a neighbor UE.

The positioning UE may transmit the request PRS using the reserved PSFCH-PRS resource and the reserved PRS ID, i.e., the request PRS ID (S1320).

According to an embodiment, the positioning UE may transmit V2X data and may simultaneously perform request PRS transmission.

The positioning UE may receive the response PRS from at least one neighbor UE in response to the transmitted request PRS (S1330).

In this case, a method of selecting the PRS ID for the response PRS, that is, the response PRS ID by the neighbor UE may be changed according to whether the sidelink positioning method is a 1:1 on-demand positioning method or a 1:N on-demand positioning method.

The response PRS is configured by being pre-mapped or paired with the request PRS, and thus an additional response PRS ID reservation procedure in the neighbor UE may not be required.

As described above with reference to FIG. 12 , the neighbor UE may receive the request PRS and may then determine a time of transmitting the response PRS based on a predefined/preconfigured request PRS-response PRS time gap.

The positioning UE may also receive a measurement result related to the transmitted request PRS from at least one neighbor UE (S1340). Here, the neighbor UE may transmit the measurement result to the positioning UE using a pre-reserved resource for transmission of V2X data.

For example, the measurement result may include at least one of Tx-Rx time difference (TRTD) information, received signal received power (RSRP) information, angle of arrival (AoA) information, or Doppler information.

The TRTD information may be time information used to measure a distance between UEs and may refer to a time taken until the neighbor UE transmits the response PRS in response to the request PRS after receiving the request PRS from the positioning UE. For example, the TRTD information may be processing time information used to transmit and receive a PRS in the neighbor UE. The positioning UE may calculate a round trip time (RTT) and may measure a distance between the positioning UE and the neighbor UE based on time information for transmitting the request PRS, time information for receiving the response PRS related to the transmitted request PRS, and TRTD information.

The RSRP information may indicate the request PRS received from the positioning UE and/or intensity information of reception power of a demodulation reference signal (DMRS).

The AoA information may indicate information on a reception angle measured by the neighbor UE with respect to the request PRS transmitted by the positioning UE.

The Doppler information may indicate information obtained by measuring the Doppler effect for the request PRS received from the positioning UE.

The positioning UE may perform positioning on at least one of an ego UE or a neighbor UE based on the Rx-Tx time difference (RTTD) information measured after the response PRS is received and the received measurement result (S1350).

Here, the Rx-Tx time difference (RTTD) may be time information used for distance measurement by the UE and may indicate a time taken until the response PRS is received in response after the positioning UE transmits the request PRS to the neighbor UE.

FIG. 14 is a diagram for explaining a method of transmitting a response PRS by a neighbor UE when a V2X data slot is pre-reserved at a time when a response PRS needs to be transmitted according to an embodiment.

Information on a candidate slot for transmitting a response PRS by a neighbor UE in response to a request PRS transmitted by a positioning UE may be predefined or dynamically determined.

For example, candidate PSFCH-PRS resource allocation information for transmitting the response PRS may be determined by a location server/LMF and/or an eNB and may then be provided to a corresponding UE through a SIB of a PSBCH or may be reserved through 1^(st)-stage SCI of the PSCCH and/or 2^(nd)-stage SCI of the PSSCH.

Referring to FIG. 14(a), a candidate PSFCH-PRS resource that is a slot for transmitting the response PRS by the neighbor UE in response to the request PRS may be reserved at an interval of a request PRS-response PRS time gap N=2 (e.g., N=2, 4, 6, and 8) during a total length of 8 slots. In this case, the neighbor UE that receives the request PRS may select any one of slots reserved as a candidate PSFCH-PRS resource and may transmit the response PRS in the selected slot.

Although the case in which the request PRS-response PRS time gap and the response PRS transmission slot period in the candidate PSFCH-PRS resource are the same has been described according to the embodiment of FIG. 14(a), this is merely an embodiment, and the request PRS-response PRS time gap and the response PRS transmission slot period in the candidate PSFCH-PRS resource may be differently set. For example, a time gap between a first slot among a plurality of slots included in the candidate PSFCH-PRS resource and a slot for transmitting a corresponding request PRS may be N slots, and a time gap between a plurality of slots included in the candidate PSFCH-PRS resource may be set to M slots. In this case, N and M may be different values.

FIG. 14(b) shows a method of selecting a response PRS transmission slot and selecting a V2X data slot for transmission of a measurement result in by a neighbor UE according to an embodiment. Referring to FIG. 14(b), it may be assumed that three slots 1410 to 1430 are reserved at an interval of 3 slots for V2X data transmission of the neighbor UE. In terms of a positioning UE, when a time (a slot) at which the response PRS needs to be received is N=4, N=4 may correspond to a second slot 1420 among V2X data slots reserved for the neighbor UE. Thus, the neighbor UE may transmit various measurement results based on the response PRS and the received request PRS to the positioning UE through the second slot 1420 among the reserved V2X data transmission slots.

FIG. 15 is a diagram for explaining a method of transmitting a response PRS by a neighbor UE when a V2X data slot is pre-reserved at a time when a response PRS needs to be transmitted according to another embodiment.

In detail, FIG. 15 is a diagram for explaining a time of a transmission time of the response PRS to be transmitted according to the candidate PSFCH-PRS resource allocation information when a V2X data slot reserved for the neighbor UE is present, and a method of transmitting the response PRS by the neighbor UE when a slot overlapping the reserved V2X data slot is not present.

FIG. 15(a) corresponds to an example of the same candidate PSFCH-PRS resource allocation as in FIG. 14(a), and thus may be replaced with the description of FIG. 14 .

Referring to FIG. 15(b), it may be assumed that three slots are reserved at a 4-slot interval for a V2X data slot for a neighbor UE. In this case, a time (a slot) at which the neighbor UE is capable of transmitting the response PRS according to candidate PSFCH-PRS resource allocation information and a slot reserved for V2X data transmission may not be present. Thus, the neighbor UE may not transmit the response PRS through a reserved V2X data slot, and instead, may independently transmit the response PRS using a PSFCH-PRS resource preconfigured (or reserved) through the request PRS-response PRS time gap. In this case, the neighbor UE may transmit various pieces of information measured based on the request PRS received from the positioning UE, i.e., a measurement result through the reserved V2X data slot. According to an embodiment, the neighbor UE may transmit the response PRS and may then transmit the measurement result to the positioning UE using the earliest (or the closest to the transmission time of the response PRS) V2X data slot 1520.

Hereinafter, a method of transmitting a response PRS by a neighbor UE when a V2X data slot reserved for a neighbor UE is not present will be described.

When there is no V2X data slot reserved by the neighbor UE, the neighbor UE may preferentially transmit only the response PRS based on candidate PSFCH-PRS resource allocation and may transmit the measurement result for the received request PRS to the positioning UE using a V2X data transmission slot reserved after a periodic or aperiodic V2X data transmission resource reservation procedure is performed.

Here, the periodic resource reservation procedure may minimize the risk of collision between resources while reducing the reliability of positioning delay and measurement information. In contrast, the aperiodic resource reservation procedure may increase the risk of collision between resources while allowing fast measurement result transmission.

FIG. 16 is a diagram for explaining a method of transmitting a response PRS by a neighbor UE when a V2X data slot is reserved at a time when a response PRS needs to be transmitted according to another embodiment of the present disclosure.

FIG. 16(a) corresponds to an example of the same candidate PSFCH-PRS resource allocation as in FIG. 14(a) or 15(b), and thus may be replaced with the description of FIG. 14 .

FIG. 16(b) shows a method of selecting a PSFCH-PRS resource for transmission of a response PRS by a neighbor UE and a method of transmitting a measurement result related to a received request PRS using an aperiodic V2X data transmission resource reservation procedure when a pre-reserved V2X data transmission resource (slot) for the neighbor UE is present.

The neighbor UE may perform the aperiodic V2X data transmission resource reservation procedure in order to rapidly transmit the measurement result related to the received request PRS. For example, when importance of positioning related to the corresponding request PRS is very high (or equal to or greater than a reference value) or priority of corresponding positioning is higher than a V2X data transmission priority, the neighbor UE may disregard pre-reserved V2X data slots 1620 and 1630 and may newly reserve (or preoccupy) a new V2X data slot 1610 by performing a predetermined aperiodic V2X data transmission resource reservation procedure and may then transmit a positioning result to the positioning UE through the newly reserved (or preoccupied) 1610. According to an embodiment, the neighbor UE may reserve (or preoccupy) the earliest slot (or the earliest idle slot) that is available from the transmission time of the response PRS and may transmit the positioning result.

According to an embodiment, the neighbor UE may reserve (or preoccupy) a slot for differentially transmitting the positioning result according to a positioning priority level. For example, when a positioning priority level is 1, the neighbor UE may reserve (or occupy) a first slot (i.e., a next slot) after a response PRS slot to transmit the positioning result, and when the positioning priority level is 2, the neighbor UE may reserve (or occupy) a second slot after the response PRS slot to transmit the positioning result.

Although the case in which the request PRS and the response PRS are transmitted through the PSFCH resource has been described according to the embodiment of FIGS. 14 to 15 , this is merely an embodiment, and according to another embodiment, it may be noted that the request PRS and the response PRS are separately transmitted through the PSCCH resource, the PSSCH resource, the DMRS resource, or a newly defined sidelink channel.

A network may dynamically determine and allocate a channel (or signal) resource for transmitting the request PRS and the response PRS for sidelink positioning in consideration of a radio channel situation.

FIG. 17 is a flowchart for explaining a sidelink broadcast positioning procedure in an AN according to an embodiment.

In the sidelink broadcast positioning procedure, only unidirectional PRS transmission to UE(s) from an anchor node (AN), and thus the request PRS and the response PRS may not be separately distinguished unlike the aforementioned sidelink on-demand positioning procedure. In addition, in a sidelink broadband positioning method, UE-based sidelink positioning, e.g., UE-based sidelink TDoA positioning may be mainly considered.

The AN may reserve a V2X data slot and may simultaneously reserve a PSFCH-PRS resource and a PRS ID for PRS transmission (S1710).

When there is a request for performing broadcast positioning from a higher layer, the AN may determine and reserve a logical slot, a PSFCH-PRS resource of which is used to transmit the PRS.

The AN may determine and reserve a PRS ID used to transmit the PRS after determining and reserving the PSFCH-PRS resource for PRS transmission.

The aforementioned PSFCH-PRS resource reservation and PRS ID reservation processes may be sequentially or simultaneously performed by the AN. According to an embodiment, the PSFCH-PRS resource reservation information and the PRS ID reservation information for sidelink broadcast positioning may be broadcast to the neighbor UE(s) through SCI of the PSCCH and/or the PSSCH. In detail, SPCI including the PSFCH-PRS resource reservation information and the PRS ID reservation information may be included in 1^(st)-stage SCI of the PSCCH and/or 2^(nd)-stage SCI of the PSSCH and may be transmitted.

In the case of the NR-V2X mode-1, the PSFCH-PRS resource and PRS ID to be reserved may be detected by an eNB.

In the case of the NR-V2X mode-2, the PSFCH-PRS resource and PRS ID to be reserved may be detected through a process of analyzing the received (or sensed) 1^(st)-stage SCI of the PSCCH and 2^(nd)-stage SCI of the PSSCH.

The AN may transmit the PRS using the reserved PSFCH-PRS resource and PRS ID (S1720). In this case, the AN may perform V2X data transmission and may simultaneously perform PRS transmission.

The UE may perform sidelink TDoA measurement using the PRS received from the neighbor AN and the absolute position information of the AN to perform positioning about an absolute position (or a state position) of the UE. In this case, the positioning result by the UE may be transmitted to the network or the neighbor UE.

Example of Communication System to which the Present Disclosure is Applied

The various descriptions, functions, procedures, proposals, methods, and/or operational flowcharts of the present disclosure described in this document may be applied to, without being limited to, a variety of fields requiring wireless communication/connection (e.g., 5G) between devices.

Hereinafter, a description will be given in more detail with reference to the drawings. In the following drawings/description, the same reference symbols may denote the same or corresponding hardware blocks, software blocks, or functional blocks unless described otherwise.

FIG. 18 illustrates a communication system applied to the present disclosure.

Referring to FIG. 18 , a communication system 1 applied to the present disclosure includes wireless devices, Base Stations (BSs), and a network. Herein, the wireless devices represent devices performing communication using Radio Access Technology (RAT) (e.g., 5G New RAT (NR)) or Long-Term Evolution (LTE)) and may be referred to as communication/radio/5G devices. The wireless devices may include, without being limited to, a robot 100 a, vehicles 100 b-1 and 100 b-2, an eXtended Reality (XR) device 100 c, a hand-held device 100 d, a home appliance 100 e, an Internet of Things (IoT) device 100 f, and an Artificial Intelligence (AI) device/server 400. For example, the vehicles may include a vehicle having a wireless communication function, an autonomous driving vehicle, and a vehicle capable of performing communication between vehicles. Herein, the vehicles may include an Unmanned Aerial Vehicle (UAV) (e.g., a drone). The XR device may include an Augmented Reality (AR)/Virtual Reality (VR)/Mixed Reality (MR) device and may be implemented in the form of a Head-Mounted Device (HMD), a Head-Up Display (HUD) mounted in a vehicle, a television, a smartphone, a computer, a wearable device, a home appliance device, a digital signage, a vehicle, a robot, etc. The hand-held device may include a smartphone, a smartpad, a wearable device (e.g., a smartwatch or a smartglasses), and a computer (e.g., a notebook). The home appliance may include a TV, a refrigerator, and a washing machine. The IoT device may include a sensor and a smartmeter. For example, the BSs and the network may be implemented as wireless devices and a specific wireless device 200 a may operate as a BS/network node with respect to other wireless devices.

The wireless devices 100 a to 100 f may be connected to the network 300 via the BSs 200. An AI technology may be applied to the wireless devices 100 a to 100 f and the wireless devices 100 a to 100 f may be connected to the AI server 400 via the network 300. The network 300 may be configured using a 3G network, a 4G (e.g., LTE) network, or a 5G (e.g., NR) network. Although the wireless devices 100 a to 100 f may communicate with each other through the BSs 200/network 300, the wireless devices 100 a to 100 f may perform direct communication (e.g., sidelink communication) with each other without passing through the BS s/network. For example, the vehicles 100 b-1 and 100 b-2 may perform direct communication (e.g. Vehicle-to-Vehicle (V2V)/Vehicle-to-everything (V2X) communication). The IoT device (e.g., a sensor) may perform direct communication with other IoT devices (e.g., sensors) or other wireless devices 100 a to 100 f.

Wireless communication/connections 150 a, 150 b, or 150 c may be established between the wireless devices 100 a to 100 f/BS 200, or BS 200/BS 200. Herein, the wireless communication/connections may be established through various RATs (e.g., 5G NR) such as uplink/downlink communication 150 a, sidelink communication 150 b (or, D2D communication), or inter BS communication (e.g. relay, Integrated Access Backhaul (IAB)). The wireless devices and the BSs/the wireless devices may transmit/receive radio signals to/from each other through the wireless communication/connections 150 a and 150 b. For example, the wireless communication/connections 150 a and 150 b may transmit/receive signals through various physical channels. To this end, at least a part of various configuration information configuring processes, various signal processing processes (e.g., channel encoding/decoding, modulation/demodulation, and resource mapping/demapping), and resource allocating processes, for transmitting/receiving radio signals, may be performed based on the various proposals of the present disclosure.

Example of Wireless Device to which Present Disclosure is Applied

FIG. 19 illustrates wireless devices applicable to the present disclosure.

Referring to FIG. 19 , a first wireless device 100 and a second wireless device 200 may transmit radio signals through a variety of RATs (e.g., LTE and NR). Herein, {the first wireless device 100, the second wireless device 200} may correspond to {the wireless device 100 x, the base station 200} and/or {the wireless device 100 x, the wireless device 100 x} of FIG. 18 .

The first wireless device 100 may include one or more processors 102 and one or more memories 104 and additionally further include one or more transceivers 106 and/or one or more antennas 108. The processor(s) 102 may control the memory(s) 104 and/or the transceiver(s) 106 and may be configured to implement the descriptions, functions, procedures, proposals, methods, and/or operational flowcharts disclosed in this document. For example, the processor(s) 102 may process information within the memory(s) 104 to generate first information/signals and then transmit radio signals including the first information/signals through the transceiver(s) 106. The processor(s) 102 may receive radio signals including second information/signals through the transceiver 106 and then store information obtained by processing the second information/signals in the memory(s) 104. The memory(s) 104 may be connected to the processor(s) 102 and may store a variety of information related to operations of the processor(s) 102. For example, the memory(s) 104 may store software code including commands for performing a part or the entirety of processes controlled by the processor(s) 102 or for performing the descriptions, functions, procedures, proposals, methods, and/or operational flowcharts disclosed in this document. Herein, the processor(s) 102 and the memory(s) 104 may be a part of a communication modem/circuit/chip designed to implement RAT (e.g., LTE or NR). The transceiver(s) 106 may be connected to the processor(s) 102 and transmit and/or receive radio signals through one or more antennas 108. Each of the transceiver(s) 106 may include a transmitter and/or a receiver. The transceiver(s) 106 may be interchangeably used with Radio Frequency (RF) unit(s). In the present disclosure, the wireless device may represent a communication modem/circuit/chip.

In detail, the UE or the vehicle may include the processor 102 and the memory 104 that are connected to the RF transceiver. The memory 104 may contain at least one program for performing an operation related to the embodiments described with reference to FIGS. 12 to 17 .

The processor 102 may transmit a request positioning reference signal (PRS) through a sidelink channel, may receive a response PRS related to the request PRS from the neighbor UE through a sidelink channel, may receive the measurement result related to the request PRS from the neighbor UE, and may perform positioning based on the response PRS and the measurement result. In this case, the processor 102 may transmit resource allocation information for transmission of the response PRS related to the request PRS to the neighbor UE, and may receive the measurement result from the neighbor UE through a resource for V2X data transmission. The processor 102 may perform an operation of determining the absolute position (or a relative position) of the UE according to an embodiment for performing a method of performing sidelink on-demand positioning using a PRS transmission resource pre-configured in the NR-V2X system described with reference to FIGS. 12 to 17 based on a program included in the memory 104.

A chip set including the processor 102 and the memory 104 may be configured. In this case, the chip set may include at least one processor and at least one memory operatively connected to the at least one processor and allowing the at least one processor to perform an operation when being executed, and the operation may include transmitting a request positioning reference signal (PRS) through a sidelink channel, receiving a response PRS related to the request PRS from a neighbor UE through a sidelink channel, receiving the measurement result related to the request PRS from the neighbor UE, and performing positioning based on the response PRS and the measurement result, and the positioning UE may transmit resource allocation information for transmission of the response PRS related to the request PRS to the neighbor UE, and may receive the measurement result from the neighbor UE through a resource for V2X data transmission. The processor 102 may perform an operation of determining an absolute position (or relative position) of the UE according to embodiments for performing a method of performing sidelink on-demand positioning using the PRS transmission resource pre-configured in the NR-V2X system described with reference to FIGS. 12 to 17 based on a program included in the memory 104.

A computer readable recording medium including at least computer program for allowing the at least one processor to perform an operation may be provided, and the operation may include transmitting a request positioning reference signal (PRS) through a sidelink channel, receiving a response PRS related to the request PRS from a neighbor UE through the sidelink channel, receiving the measurement result related to the request PRS from the neighbor UE, and performing positioning based on the response PRS and the measurement result, and the positioning UE may transmit resource allocation information for transmission of the response PRS related to the request PRS to the neighbor UE and may receive the measurement result from the neighbor UE through a resource for V2X data transmission. The processor 102 may perform an operation for determining the absolute position (or relative position) of the UE according to an embodiment for performing a method of performing sidelink on-demand positioning using the PRS transmission resource pre-configured in the NR-V2X system described with reference to FIGS. 12 to 17 based on a program included in the memory 104.

The second wireless device 200 may include one or more processors 202 and one or more memories 204 and additionally further include one or more transceivers 206 and/or one or more antennas 208. The processor(s) 202 may control the memory(s) 204 and/or the transceiver(s) 206 and may be configured to implement the descriptions, functions, procedures, proposals, methods, and/or operational flowcharts disclosed in this document. For example, the processor(s) 202 may process information within the memory(s) 204 to generate third information/signals and then transmit radio signals including the third information/signals through the transceiver(s) 206. The processor(s) 202 may receive radio signals including fourth information/signals through the transceiver(s) 106 and then store information obtained by processing the fourth information/signals in the memory(s) 204. The memory(s) 204 may be connected to the processor(s) 202 and may store a variety of information related to operations of the processor(s) 202. For example, the memory(s) 204 may store software code including commands for performing a part or the entirety of processes controlled by the processor(s) 202 or for performing the descriptions, functions, procedures, proposals, methods, and/or operational flowcharts disclosed in this document. Herein, the processor(s) 202 and the memory(s) 204 may be a part of a communication modem/circuit/chip designed to implement RAT (e.g., LTE or NR). The transceiver(s) 206 may be connected to the processor(s) 202 and transmit and/or receive radio signals through one or more antennas 208. Each of the transceiver(s) 206 may include a transmitter and/or a receiver. The transceiver(s) 206 may be interchangeably used with RF unit(s). In the present disclosure, the wireless device may represent a communication modem/circuit/chip.

The processor 202 may transmit a request positioning reference signal (PRS) through a sidelink channel, may receive a response PRS related to the request PRS from the neighbor UE through the sidelink channel, may receive the measurement result related to the request PRS from the neighbor UE, and may perform positioning based on the response PRS and the measurement result. In this case, resource allocation information for transmission of the response PRS related to the request PRS may be transmitted to the neighbor UE, and the measurement result may be received from the neighbor UE through a resource for V2X data transmission. The processor 202 may perform an operation of determining an absolute position (or absolute position) of the UE according to embodiments for performing a method of performing sidelink on-demand positioning using a PRS transmission resource pre-configured in the NR-V2X system described with reference to FIGS. 12 to 17 based on a program included in the memory 204.

A chip set including the processor 202 and the memory 204 may be configured. In this case, the chip set may include at least one processor and at least one memory operatively connected to the at least one processor and allowing the at least one processor to perform an operation when being executed, and the operation may include transmitting a request positioning reference signal (PRS) through a sidelink channel, receiving a response PRS related to the request PRS from a neighbor UE through a sidelink channel, receiving the measurement result related to the request PRS from the neighbor UE, and performing positioning based on the response PRS and the measurement result, and the positioning UE may transmit resource allocation information for transmission of the response PRS related to the request PRS to the neighbor UE and may receive the measurement result from the neighbor UE through a resource for V2X data transmission. The processor 202 may perform an operation for determining the absolute position of the UE according to embodiments for performing a method of performing sidelink on-demand positioning using a PRS transmission resource pre-configured in the NR-V2X system described with reference to FIGS. 12 to 17 based on a program included in the memory 204.

Hereinafter, hardware elements of the wireless devices 100 and 200 will be described more specifically. One or more protocol layers may be implemented by, without being limited to, one or more processors 102 and 202. For example, the one or more processors 102 and 202 may implement one or more layers (e.g., functional layers such as PHY, MAC, RLC, PDCP, RRC, and SDAP). The one or more processors 102 and 202 may generate one or more Protocol Data Units (PDUs) and/or one or more Service Data Unit (SDUs) according to the descriptions, functions, procedures, proposals, methods, and/or operational flowcharts disclosed in this document. The one or more processors 102 and 202 may generate messages, control information, data, or information according to the descriptions, functions, procedures, proposals, methods, and/or operational flowcharts disclosed in this document. The one or more processors 102 and 202 may generate signals (e.g., baseband signals) including PDUs, SDUs, messages, control information, data, or information according to the descriptions, functions, procedures, proposals, methods, and/or operational flowcharts disclosed in this document and provide the generated signals to the one or more transceivers 106 and 206. The one or more processors 102 and 202 may receive the signals (e.g., baseband signals) from the one or more transceivers 106 and 206 and acquire the PDUs, SDUs, messages, control information, data, or information according to the descriptions, functions, procedures, proposals, methods, and/or operational flowcharts disclosed in this document.

The one or more processors 102 and 202 may be referred to as controllers, microcontrollers, microprocessors, or microcomputers. The one or more processors 102 and 202 may be implemented by hardware, firmware, software, or a combination thereof. As an example, one or more Application Specific Integrated Circuits (ASICs), one or more Digital Signal Processors (DSPs), one or more Digital Signal Processing Devices (DSPDs), one or more Programmable Logic Devices (PLDs), or one or more Field Programmable Gate Arrays (FPGAs) may be included in the one or more processors 102 and 202. The descriptions, functions, procedures, proposals, methods, and/or operational flowcharts disclosed in this document may be implemented using firmware or software and the firmware or software may be configured to include the modules, procedures, or functions. Firmware or software configured to perform the descriptions, functions, procedures, proposals, methods, and/or operational flowcharts disclosed in this document may be included in the one or more processors 102 and 202 or stored in the one or more memories 104 and 204 so as to be driven by the one or more processors 102 and 202. The descriptions, functions, procedures, proposals, methods, and/or operational flowcharts disclosed in this document may be implemented using firmware or software in the form of code, commands, and/or a set of commands.

The one or more memories 104 and 204 may be connected to the one or more processors 102 and 202 and store various types of data, signals, messages, information, programs, code, instructions, and/or commands. The one or more memories 104 and 204 may be configured by Read-Only Memories (ROMs), Random Access Memories (RAMs), Electrically Erasable Programmable Read-Only Memories (EPROMs), flash memories, hard drives, registers, cash memories, computer-readable storage media, and/or combinations thereof. The one or more memories 104 and 204 may be located at the interior and/or exterior of the one or more processors 102 and 202. The one or more memories 104 and 204 may be connected to the one or more processors 102 and 202 through various technologies such as wired or wireless connection.

The one or more transceivers 106 and 206 may transmit user data, control information, and/or radio signals/channels, mentioned in the methods and/or operational flowcharts of this document, to one or more other devices. The one or more transceivers 106 and 206 may receive user data, control information, and/or radio signals/channels, mentioned in the descriptions, functions, procedures, proposals, methods, and/or operational flowcharts disclosed in this document, from one or more other devices. For example, the one or more transceivers 106 and 206 may be connected to the one or more processors 102 and 202 and transmit and receive radio signals. For example, the one or more processors 102 and 202 may perform control so that the one or more transceivers 106 and 206 may transmit user data, control information, or radio signals to one or more other devices. The one or more processors 102 and 202 may perform control so that the one or more transceivers 106 and 206 may receive user data, control information, or radio signals from one or more other devices. The one or more transceivers 106 and 206 may be connected to the one or more antennas 108 and 208 and the one or more transceivers 106 and 206 may be configured to transmit and receive user data, control information, and/or radio signals/channels, mentioned in the descriptions, functions, procedures, proposals, methods, and/or operational flowcharts disclosed in this document, through the one or more antennas 108 and 208. In this document, the one or more antennas may be a plurality of physical antennas or a plurality of logical antennas (e.g., antenna ports). The one or more transceivers 106 and 206 may convert received radio signals/channels etc. from RF band signals into baseband signals in order to process received user data, control information, radio signals/channels, etc. using the one or more processors 102 and 202. The one or more transceivers 106 and 206 may convert the user data, control information, radio signals/channels, etc. processed using the one or more processors 102 and 202 from the base band signals into the RF band signals. To this end, the one or more transceivers 106 and 206 may include (analog) oscillators and/or filters.

Examples of Application of Wireless Device Applicable to the Present Disclosure

FIG. 20 illustrates another example of a wireless device applied to the present disclosure. The wireless device may be implemented in various forms according to a use-case/service (refer to FIG. 28 ).

Referring to FIG. 20 wireless devices 100 and 200 may correspond to the wireless devices 100 and 200 of FIG. 19 and may be configured by various elements, components, units/portions, and/or modules. For example, each of the wireless devices 100 and 200 may include a communication unit 110, a control unit 120, a memory unit 130, and additional components 140. The communication unit may include a communication circuit 112 and transceiver(s) 114. For example, the communication circuit 112 may include the one or more processors 102 and 202 and/or the one or more memories 104 and 204 of FIG. 19 . For example, the transceiver(s) 114 may include the one or more transceivers 106 and 206 and/or the one or more antennas 108 and 208 of FIG. 19 . The control unit 120 is electrically connected to the communication unit 110, the memory 130, and the additional components 140 and controls overall operation of the wireless devices. For example, the control unit 120 may control an electric/mechanical operation of the wireless device based on programs/code/commands/information stored in the memory unit 130. The control unit 120 may transmit the information stored in the memory unit 130 to the exterior (e.g., other communication devices) via the communication unit 110 through a wireless/wired interface or store, in the memory unit 130, information received through the wireless/wired interface from the exterior (e.g., other communication devices) via the communication unit 110.

The additional components 140 may be variously configured according to types of wireless devices. For example, the additional components 140 may include at least one of a power unit/battery, input/output (I/O) unit, a driving unit, and a computing unit. The wireless device may be implemented in the form of, without being limited to, the robot (100 a of FIG. 18 ), the vehicles (100 b-1 and 100 b-2 of FIG. 18 ), the XR device (100 c of FIG. 18 ), the hand-held device (100 d of FIG. 18 ), the home appliance (100 e of FIG. 18 ), the IoT device (100 f of FIG. 18 ), a digital broadcast terminal, a hologram device, a public safety device, an MTC device, a medicine device, a FinTech device (or a finance device), a security device, a climate/environment device, the AI server/device (400 of FIG. 18 ), the BSs (200 of FIG. 18 ), a network node, etc. The wireless device may be used in a mobile or fixed place according to a use-example/service.

In FIG. 20 , the entirety of the various elements, components, units/portions, and/or modules in the wireless devices 100 and 200 may be connected to each other through a wired interface or at least a part thereof may be wirelessly connected through the communication unit 110. For example, in each of the wireless devices 100 and 200, the control unit 120 and the communication unit 110 may be connected by wire and the control unit 120 and first units (e.g., 130 and 140) may be wirelessly connected through the communication unit 110. Each element, component, unit/portion, and/or module within the wireless devices 100 and 200 may further include one or more elements. For example, the control unit 120 may be configured by a set of one or more processors. As an example, the control unit 120 may be configured by a set of a communication control processor, an application processor, an electronic control unit (ECU), a graphical processing unit, and a memory control processor. As another example, the memory 130 may be configured by a RAM, a DRAM, a ROM, a flash memory, a volatile memory, a non-volatile memory, and/or a combination thereof.

Example of a Vehicle or an Autonomous Driving Vehicle to which the Present Disclosure is Applied

FIG. 21 illustrates a vehicle or an autonomous driving vehicle applied to the present disclosure. The vehicle or autonomous driving vehicle may be implemented by a mobile robot, a car, a train, a manned/unmanned Aerial Vehicle (AV), a ship, etc.

Referring to FIG. 21 , a vehicle or autonomous driving vehicle 100 may include an antenna unit 108, a communication unit 110, a control unit 120, a driving unit 140 a, a power supply unit 140 b, a sensor unit 140 c, and an autonomous driving unit 140 d. The antenna unit 108 may be configured as a part of the communication unit 110. The blocks 110/130/140 a to 140 d correspond to the blocks 110/130/140 of FIG. 20 , respectively.

The antenna unit 108 may include a plurality of distributed antennas distributed and arranged in the vehicle. The position of the distributed antennas arranged in the vehicle may be different depending on the vehicle. A reference point indicating a relative position in the vehicle of the distributed antenna may be predefined and may be recorded and maintained in a memory included in the vehicle. In this case, the reference point may be differently defined according to the vehicle.

The communication unit 110 may transmit and receive signals (e.g., data and control signals) to and from external devices such as other vehicles, BSs (e.g., gNBs and road side units), and servers. The control unit 120 may perform various operations by controlling elements of the vehicle or the autonomous driving vehicle 100. The control unit 120 may include an Electronic Control Unit (ECU). The driving unit 140 a may cause the vehicle or the autonomous driving vehicle 100 to drive on a road. The driving unit 140 a may include an engine, a motor, a powertrain, a wheel, a brake, a steering device, etc. The power supply unit 140 b may supply power to the vehicle or the autonomous driving vehicle 100 and include a wired/wireless charging circuit, a battery, etc. The sensor unit 140 c may acquire a vehicle state, ambient environment information, user information, etc. The sensor unit 140 c may include an Inertial Measurement Unit (IMU) sensor, a collision sensor, a wheel sensor, a speed sensor, a slope sensor, a weight sensor, a heading sensor, a position module, a vehicle forward/backward sensor, a battery sensor, a fuel sensor, a tire sensor, a steering sensor, a temperature sensor, a humidity sensor, an ultrasonic sensor, an illumination sensor, a pedal position sensor, etc. The autonomous driving unit 140 d may implement technology for maintaining a lane on which a vehicle is driving, technology for automatically adjusting speed, such as adaptive cruise control, technology for autonomously driving along a determined path, technology for driving by automatically setting a path if a destination is set, and the like.

For example, the communication unit 110 may receive map data, traffic information data, etc. from an external server. The autonomous driving unit 140 d may generate an autonomous driving path and a driving plan from the obtained data. The control unit 120 may control the driving unit 140 a such that the vehicle or the autonomous driving vehicle 100 may move along the autonomous driving path according to the driving plan (e.g., speed/direction control). In the middle of autonomous driving, the communication unit 110 may aperiodically/periodically acquire recent traffic information data from the external server and acquire surrounding traffic information data from neighboring vehicles. In the middle of autonomous driving, the sensor unit 140 c may obtain a vehicle state and/or surrounding environment information. The autonomous driving unit 140 d may update the autonomous driving path and the driving plan based on the newly obtained data/information. The communication unit 110 may transfer information about a vehicle position, the autonomous driving path, and/or the driving plan to the external server. The external server may predict traffic information data using AI technology, etc., based on the information collected from vehicles or autonomous driving vehicles and provide the predicted traffic information data to the vehicles or the autonomous driving vehicles.

Here, a wireless communication technology implemented in the wireless devices XXX and YYY in the present disclosure may include Narrowband Internet of Things for low power communication as well as LTE, NR, and 6G. In this case, for example, the NB-IoT technology may be an example of a Low Power Wide Area Network (LPWAN) technology and may be implemented in standards such as LTE Cat NB1 and/or LTE Cat NB2, and is not limited to the above-described name. Additionally or alternatively, the wireless communication technology implemented in the wireless devices XXX and YYY may be performed based on the LTE-M technology. In this case, for example, the LTE-M technology may be an example of the LPWAN technology and may be called various terms such as enhanced Machine Type Communication (eMTC). For example, the LTE-M technology may be implemented as at least one of various standards such as 1) LTE CAT (LTE Category) 0, 2) LTE Cat M1, 3) LTE Cat M2, 4) LTE non-BL (non-Bandwidth Limited), 5) LTE-MTC, 6) LTE Machine Type Communication, and/or 7) LTE M and may not be limited to the aforementioned terms. Additionally or alternatively, the wireless communication technology implemented in the wireless devices XXX and YYY according to the present disclosure may include at least one of ZigBee, Bluetooth, or Low Power Wide Area Network (LPWAN) in consideration of low power communication and is not limited to the aforementioned terms. For example, the ZigBee technology may generate personal area networks (PAN) associated with small/low-power digital communication based on various embodiments of the present disclosure described above are combinations of elements and features of the present disclosure.

The elements or features may be considered selective unless otherwise mentioned. Each element or feature may be practiced without being combined with other elements or features. Further, an embodiment of the present disclosure may be constructed by combining parts of the elements and/or features. Operation orders described in embodiments of the present disclosure may be rearranged. Some constructions of any one embodiment may be included in another embodiment and may be replaced with corresponding constructions of another embodiment. It is obvious to those skilled in the art that claims that are not explicitly cited in each other in the appended claims may be presented in combination as an embodiment of the present disclosure or included as a new claim by a subsequent amendment after the application is filed.

In this document, the embodiments of the present disclosure have been described centering on a data transmission and reception relationship between a UE and a BS. The transmission and reception relationship may be equally/similarly extended to signal transmission/reception between a UE and a relay or between a BS and a relay. In this document, a specific operation described as performed by the BS may be performed by an upper node of the BS as necessary. In other words, it will be obvious to those skilled in the art that various operations for enabling the base station to communicate with the terminal in a network composed of several network nodes including the base station will be conducted by the base station or other network nodes other than the base station. The term “base station (BS)” may be replaced with a fixed station, Node-B, eNode-B (eNB), or an access point as necessary. The term “terminal” may also be replaced with a user

The embodiments according to the present disclosure may be implemented by various means, for example, hardware, firmware, software, or a combination thereof. In a hardware configuration, the embodiments of the present disclosure may be achieved by at least one of application specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), processors, controllers, microcontrollers, microprocessors, etc.

In a firmware or software configuration, the embodiments of the present disclosure may be implemented in the form of a module, a procedure, a function, etc. for performing the above-described functions or operations. Software code may be stored in the memory and executed by the processor. The memory is located at the interior or exterior of the processor and may transmit and receive data to and from the processor via various known means.

Various embodiments of the present disclosure may be carried out in other specific ways than those set forth herein without departing from the spirit and essential characteristics of the present disclosure. The above implementations are therefore to be construed in all aspects as illustrative and not restrictive. The scope of the disclosure should be determined by the appended claims and their legal equivalents, not by the above description, and all changes coming within the meaning and equivalency range of the appended claims are intended to be embraced therein.

INDUSTRIAL AVAILABILITY

The above-described embodiments of the present disclosure may be applied to various devices for communication through sidelink. 

1. A method of performing on-demand positioning by a positioning user equipment (UE) in a new radio-vehicle to everything (NR-V2X) communication system, the method comprising: transmitting a request positioning reference signal (PRS) through a sidelink channel; receiving a response PRS related to the request PRS from a neighbor UE through the sidelink channel; receiving a measurement result related to the request PRS from the neighbor UE; and performing positioning based on the response PRS and the measurement result, wherein the positioning UE transmits resource allocation information for transmission of the response PRS related to the request PRS to the neighbor UE and receives the measurement result through a resource for V2X data transmission.
 2. The method of claim 1, wherein the sidelink channel includes a physical sidelink feedback channel (PSFCH) for transmission of HARQ feedback information for sidelink data, and a resource for the request PRS and a resource for the response PRS are allocated to one PSFCH resource or the resource for the request PRS and the resource for the response PRS are allocated to different PSFCH resources.
 3. The method of claim 2, wherein, when the resource for the request PRS and the resource for the response PRS are allocated to the different PSFCH resources, a plurality of PSFCH-PRS groups including contiguous or non-contiguous slots are each allocated for transmission of the request PRS and transmission of the response PRS.
 4. The method of claim 1, wherein the resource allocation information for transmission of the response PRS is transmitted to the neighbor UE through at least one of 1^(st)-stage sidelink control information (SCI) of a physical sidelink control channel (PSCCH) or 2^(nd)-stage SCI of a PSSCH.
 5. The method of claim 1, wherein the resource allocation information for transmission of the response PRS includes information on a time gap between a transmission time of the request PRS in the positioning UE and a transmission time of the response PRS in the neighbor UE.
 6. The method of claim 1, wherein a request PRS ID related to the request PRS and a response PRS ID related to the response PRS are the same.
 7. The method of claim 1, wherein a relationship between a response PRS ID related to the response PRS and a request PRS ID related to the request PRS is pre-mapped or paired, a number of the response PRS IDs mapped or paired with the request PRS ID is determined based on an on-demand positioning mode, and the on-demand positioning mode includes a 1:1 unicast positioning mode and a 1:N groupcast positioning mode.
 8. The method of claim 1, wherein the resource allocation information for transmission of the response PRS includes information on a plurality of candidate slots to be selected by the neighbor UE for transmission of the response PRS, and the plurality of candidate slots are periodically allocated.
 9. The method of claim 8, wherein the measurement result is received through a slot overlapping the candidate slot selected by the neighbor UE for transmission of the response PRS or a closest slot among a plurality of slots reserved for the V2X data transmission.
 10. The method of claim 8, wherein the measurement result is received through the V2X data transmission slot reserved or preoccupied based on a positioning priority related to the request PRS.
 11. A user equipment (UE) for performing on-demand positioning in a new radio-vehicle to everything (NR-V2X) communication system, the UE comprising: a radio frequency (RF) transceiver; and a processor connected to the RF transceiver, wherein the processor transmits a request positioning reference signal (PRS) through a sidelink channel, receives a response PRS related to the request PRS from a neighbor UE through the sidelink channel, receives a measurement result related to the request PRS from the neighbor UE, and performs positioning based on the response PRS and the measurement result, and wherein the UE transmits resource allocation information for transmission of the response PRS related to the request PRS to the neighbor UE and receives the measurement result through a resource for V2X data transmission.
 12. The UE of claim 11, wherein the sidelink channel includes a physical sidelink feedback channel (PSFCH) for transmission of HARQ feedback information for sidelink data, and a resource for the request PRS and a resource for the response PRS are allocated to one PSFCH resource or the resource for the request PRS and the resource for the response PRS are allocated to different PSFCH resources.
 13. The UE of claim 12, wherein, when the resource for the request PRS and the resource for the response PRS are allocated to the different PSFCH resources, a plurality of PSFCH-PRS groups including contiguous or non-contiguous slots are each allocated for transmission of the request PRS and transmission of the response PRS.
 14. The UE of claim 11, wherein the resource allocation information for transmission of the response PRS is transmitted to the neighbor UE through at least one of 1st-stage sidelink control information (SCI) of a physical sidelink control channel (PSCCH) or 2^(nd)-stage SCI of a PSSCH.
 15. The UE of claim 11, wherein the resource allocation information for transmission of the response PRS includes information on a time gap between a transmission time of the request PRS in the positioning UE and a transmission time of the response PRS in the neighbor UE, and wherein a request PRS ID related to the request PRS and a response PRS ID related to the response PRS are the same.
 16. (canceled)
 17. The UE of claim 11, wherein a relationship between a response PRS ID related to the response PRS and a request PRS ID related to the request PRS is pre-mapped or paired, a number of the response PRS IDs mapped or paired with the request PRS ID is determined based on an on-demand positioning mode, and the on-demand positioning mode includes a 1:1 unicast positioning mode and a 1:N groupcast positioning mode.
 18. The UE of claim 11, wherein the resource allocation information for transmission of the response PRS includes information on a plurality of candidate slots to be selected by the neighbor UE for transmission of the response PRS, and the plurality of candidate slots are periodically allocated.
 19. The UE of claim 18, wherein the measurement result is received through a slot overlapping the candidate slot selected by the neighbor UE for transmission of the response PRS or a closest slot among a plurality of slots reserved for the V2X data transmission.
 20. The UE of claim 18, wherein the measurement result is received through the V2X data transmission slot reserved or preoccupied based on a positioning priority related to the request PRS.
 21. A processor for performing operations for on-demand positioning of a positioning user equipment (UE) in a new radio-vehicle to everything (NR-V2X) communication system, the operations comprising: transmitting a request positioning reference signal (PRS) through a sidelink channel; receiving a response PRS related to the request PRS from a neighbor UE through the sidelink channel; receiving a measurement result related to the request PRS from the neighbor UE; and performing positioning based on the response PRS and the measurement result, wherein the processor transmits resource allocation information for transmission of the response PRS related to the request PRS to the neighbor UE and receives the measurement result through a resource for V2X data transmission. 